Home
Supplier Discovery
Construction & Decoration
Scaffolding
Adjustable Coupler Factories & Companies
Filter
Category
Construction & Decoration
Electrical & Electronics
Manufacturing & Processing Machinery
Metallurgy, Mineral & Energy
Transportation
More
Management Certification
ISO9001:2008
ISO14001:2004
Others
ISO9001:2015
ISO14001:2015
More
R&D Capacity
OEM
ODM
Own Brand
Others
Annual Revenue
<1 Million USD
1 ~ 2.5 Million USD
2.5 ~ 5 Million USD
5 ~ 10 Million USD
10 ~ 50 Million USD
More
No.of Employees
Less than 5 People
5-50 People
51-200 People
201-500 People
501-1000 People
More
Province & Region
Anhui
Beijing
Chongqing
Fujian
Guangdong
More
about adjustable coupler
Technological Innovation
Reliable Supply Chains
Substantial Manufacturing Capabilities
adjustable coupler
700+ factories verified
Shandong North Autotech Co. Ltd
4 yrs
·
5.0
·
Trading Company
Send Inquiry
Ball Mount 15000lbs Casting/Forged Heavy Duty Adjustable Hitch Coupler Tow Coupler Trailer Coupler with Straight Tongue
US$
20.00
-
30.00
500 Pieces
(MOQ)
Quick-Lock 12500lbs Capacity Adjustable Trailer Coupler for The Trailer
US$
2.00
-
9.00
100 Pieces
(MOQ)
Professional Made 14000lbs Capacity Adjustable Trailer Coupler for Sale
US$
2.00
-
9.00
100 Pieces
(MOQ)
4 PC Keyed-Alike Trailer Lock Set
US$
3.00
-
8.00
100 Pieces
(MOQ)
1/4
Shijiazhuang Hanpiao Metal Work Co., Ltd.
24 yrs
·
5.0
·
Manufacturer/Factory
Send Inquiry
Adjustable Fixed Clamp Swivel Clamp Scaffolding Coupler for Versatile Use
US$
0.052
3,000 Pieces
(MOQ)
Scaffold Clamp Adjustable Scaffold Coupler for Versatile Applications
US$
0.53
-
0.65
5,000 Pieces
(MOQ)
Adjustable Forged Scaffolding Clamp Scaffold Coupler BS1139 for Flexible Use.
US$
0.52
3,000 Pieces
(MOQ)
Formwork Accessories Adjustable Scaffold Coupler for Easy Assembly
US$
0.53
-
0.65
5,000 Pieces
(MOQ)
1/4
Yantai Li gong Machinery Equipment Co., Ltd.
Send Inquiry
LG S45 Quick Coupler Adjustable Width for Site Cleanup OEM Available PRO Series
US$
420.00
-
455.00
1 Piece
(MOQ)
ISO Approved S30 Quick Coupler for Demolition Work Adjustable Width LG S60 2025
US$
190.00
-
220.00
1 Piece
(MOQ)
S30 S45 Quick Coupler for Landscaping CE Certified Adjustable Width LG Max Range
US$
180.00
-
210.00
1 Piece
(MOQ)
S40 S60 Quick Coupler for Demolition Work Patented Design Adjustable Width LG Model 2025
US$
240.00
-
280.00
1 Piece
(MOQ)
1/4
Cangzhou Hanyue International Trade Co., LTD
Send Inquiry
Building Construction Scaffolding Drop Steel Angle Adjustable Clamp/Swivel Coupler
US$
0.30
-
0.50
1,000 Pieces
(MOQ)
Construction Galvanized Scaffold Ringlock System Scaffolding Adjustable Scaffolding Coupler
US$
8.00
-
15.00
1,000 Pieces
(MOQ)
China Actory Outlet Store Formwork Scaffolding/Scaffold Adjustable Screw Joint Coupler Building Material Q235 Hardware
US$
1.00
-
3.00
1,000 Pieces
(MOQ)
Building Construction Forged Scaffolding Clamp Scaffold Beam Clamps Scaffolding Drop Forged Steel Angle Adjustable Clamp Swivel Coupler
US$
0.50
-
1.00
1,000 Pieces
(MOQ)
1/4
Shijiazhuang Jingtie Tengfei Tools and Measuring Instruments Co., Ltd.
18 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
Premium Adjustable Train Coupler with Reliable Locomotive Coupling Device
US$
500.00
-
1,000.00
10 Pieces
(MOQ)
Premium Railway Locomotive Coupling Hook for Adjustable Train Coupler
US$
500.00
-
1,000.00
10 Pieces
(MOQ)
Premium Train Coupler with Adjustable Railway Locomotive Coupling Hook
US$
500.00
-
1,000.00
10 Pieces
(MOQ)
Reliable Railway Locomotive Coupling Hook for Adjustable Train Coupler
US$
500.00
-
1,000.00
10 Pieces
(MOQ)
1/4
QINGDAO YONGXIN RIGGING CO., LTD.
15 yrs
·
5.0
·
Manufacturer/Factory
Send Inquiry
a Type 2" Ball Adjustable Tow Bar Kit Trailer Coupler
US$
6.00
-
16.00
500 Pieces
(MOQ)
2-5/16" Inch Hitch Ball Channel Mount Adjustable Trailer Coupler and 5-Position Channel Bracket Kit
US$
6.00
-
16.00
500 Pieces
(MOQ)
Trailer Manufacturers Adjustable Coupler Types of Trailer Coupler High-Strength Steel
US$
6.00
-
16.00
500 Pieces
(MOQ)
Wholesale High Quality 2-5/16" Hitch Ball Painted Adjustable Trailer Coupler
US$
6.00
-
16.00
500 Pieces
(MOQ)
1/4
Cangzhou Zhite Building Materials Co., LTD
5 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
OEM Japanese Style Rotating Swivel Coupler for Adjustable Scaffold Scaffolding Tube Connections in Building
US$
1.31
-
1.45
1,000 Pieces
(MOQ)
Adjustable Angle Suspension Coupler for Complex Scaffolding Systems
US$
1.31
-
1.45
1,000 Pieces
(MOQ)
Durable Adjustable Scaffolding Scaffold Swivel Coupler for Secure Connection of Steel Pipes on Construction Sites
US$
1.31
-
1.45
1,000 Pieces
(MOQ)
Adjustable Steel Rotating Clamp Coupler for Multi-Angle Scaffolding Tube Joint Installations
US$
1.31
-
1.45
1,000 Pieces
(MOQ)
1/4
Ningbo Soaring Trailer Parts Co., Limited
5.0
Send Inquiry
2500kgs 50mm Round Functional Trailer Towing Hitch Coupling European Type Adjustable Coupler
US$
3.25
-
3.85
500 Pieces
(MOQ)
2-5/16 Inch 7000lbs Adjustable Channel Mount Heavy Duty Trailer Towing Coupler with Trigger Latch
US$
13.80
-
15.80
100 Pieces
(MOQ)
14000lbs Capacity 2 Inch Black Trailer Heavy Duty Ball Hitch Adjustable Coupler
US$
14.28
-
15.88
200 Pieces
(MOQ)
2-5/16 Inch Ball Heavy Duty a-Frame Trailer Adjustable Coupler with Capacity 12500lbs
US$
14.28
-
15.88
200 Pieces
(MOQ)
1/4
TAIZHOU HUANGYAN TENGFEI MACHINERY CO., LTD.
3 yrs
·
Manufacturer/Factory
Send Inquiry
Adjustable Trailer Coupler for Enhanced Towing Performance and Safety
US$
13.00
-
18.00
50 Pieces
(MOQ)
Adjustable Trailer Coupler with Safety Lock and Durable Design
US$
28.00
-
30.00
50 Pieces
(MOQ)
Adjustable Trailer Coupler with Locking Mechanism for Safety
US$
6.00
-
10.00
50 Pieces
(MOQ)
Adjustable Trailer Coupler with Safety Lock and Easy Installation
US$
30.00
-
40.00
50 Pieces
(MOQ)
1/4
Tianjin Bridge Steel Co., Ltd.
4 yrs
·
Trading Company
Send Inquiry
Adjustable Swivel Clamp Coupler for Secure Scaffolding Support
US$
0.80
-
1.10
1,000 Pieces
(MOQ)
Adjustable Scaffolding Swivel Clamp Coupler for Secure Rigging
US$
0.80
-
1.10
1,000 Pieces
(MOQ)
Building Construction Accessories Adjustable Clamp Swivel Coupler
US$
0.80
-
1.10
1,000 Pieces
(MOQ)
Adjustable Scaffold Prop Swivel Couplers for Secure Fittings
US$
1.12
1,000 Pieces
(MOQ)
1/4
NINGBO SANHE REFRIGERATION CO., LTD.
5.0
Send Inquiry
1/4 Inch Quick Couplers for Refrigeration Special Adjustable QC-13h Quick Coupler for Air Conditioner
US$
1.99
-
8.99
100 Pieces
(MOQ)
Adjustable Quick Coupler (QCM-L/H) with Good Price
US$
1.99
-
8.99
100 Pieces
(MOQ)
1/4 Inch Quick Couplers for Refrigeration Special Adjustable QC-18h Quick Coupler for Air Conditioner
US$
1.99
-
8.99
100 Pieces
(MOQ)
1/4 Inch Quick Couplers for Refrigeration Special Adjustable QC-L Quick Coupler for Air Conditioner
US$
1.99
-
8.99
100 Pieces
(MOQ)
1/4
Tianjin Huayou Scaffolding Co., Ltd.
Send Inquiry
Building Accessories Scaffolding Drop Forged Steel Angle Adjustable Clamp/Swivel Coupler
US$
0.95
-
2.00
1 Piece
(MOQ)
En-74 Building Construction Forged Scaffolding Clamp Scaffold Beam Clamps Scaffolding Drop Forged Steel Angle Adjustable Clamp Swivel Coupler for Sale
US$
0.95
-
5.00
1 Piece
(MOQ)
Building Construction Forged Scaffolding Clamp Scaffold Beam Clamps Scaffolding Drop Forged Steel Angle Adjustable Clamp Swivel Coupler
US$
0.95
-
5.00
1 Piece
(MOQ)
Building Construction Material JIS/BS Standard Scaffolding Drop Forged Steel Angle Adjustable Clamp/Swivel Coupler
US$
0.95
-
2.00
1 Piece
(MOQ)
1/4
Qingdao HaiHui Vehicle Parts Co., Ltd.
5.0
Send Inquiry
European-Style Coupler 1 7/8" Suit Ball Size 2000 Kg Capacity Trailer Adjustable Coupler
US$
1.00
-
50.00
50 Pieces
(MOQ)
Black Heavy Duty Cast Adjustable Trailer Coupler 2"" 7000lbs Capacity Channel-Mount Coupler
US$
1.00
-
50.00
50 Pieces
(MOQ)
2000kg Adjustable Pintle Ring Trailer Coupler
US$
1.00
-
50.00
50 Pieces
(MOQ)
5000lbs 2-5/16" Suit Ball Size a-Frame Trailer Coupler Adjustable Trailer Couplers
US$
1.00
-
50.00
50 Pieces
(MOQ)
1/4
Rizhao Canghai Machinery Co., Ltd.
2 yrs
·
5.0
·
Trading Company
Send Inquiry
Construction Adjustable Scaffolding Joint Clamp Hardware Scaffold Wedge Coupler
US$
1.74
-
1.80
1,500 Pieces
(MOQ)
Heavy-Duty Scaffolding System Adjustable European Forged Double Clamp Scaffold Coupler
US$
1.74
-
1.80
1,000 Pieces
(MOQ)
Adjustable European Construction Drop Forged Clamp Scaffolding Clamp Coupler
US$
2.02
-
2.08
1,000 Pieces
(MOQ)
Building Material Construction Scaffold Connector Adjustable Steel Scaffolding Guardrail Coupler
US$
2.42
-
2.50
1,000 Pieces
(MOQ)
1/4
Qing Dao Xiang Bai Mu Machinery Co., Ltd.
11 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
5000lbs 2" 2-5/16" a Frame Trailer Coupler Adjustable Coupler Trailer
US$
5.00
100 Pieces
(MOQ)
Heavy Duty Cast Adjustable Trailer Coupler 2-5/16 in, 15000lbs Capacity Channel-Mount Coupler
US$
6.90
100 Pieces
(MOQ)
Square Adjustable Gooseneck Trailer Coupler, 30, 000 Lbs Capacity for Trailer/RV/Boat
US$
5.00
100 Pieces
(MOQ)
Black Heavy Duty Cast Adjustable Trailer Coupler 2", 7000lbs Capacity Channel-Mount Coupler
US$
6.90
100 Pieces
(MOQ)
1/4
CANGZHOU SHEEN METAL PRODUCTS CO.,LTD.
9 yrs
Send Inquiry
Immediate Use Scaffold Coupler and Adjustable Tube for All Projects
US$
1.00
-
3.00
2,000 Pieces
(MOQ)
Spot Supply Adjustable Scaffold Tube and Couplers for Immediate Use
US$
1.00
-
3.00
2,000 Pieces
(MOQ)
Multidirectional Scaffolding Parts: Adjustable Scaffold Tube and Couplers
US$
1.00
-
3.00
2,000 Pieces
(MOQ)
Customizable Adjustable Scaffold Tube and Couplers for Easy Assembly
US$
1.00
-
3.00
2,000 Pieces
(MOQ)
1/4
Wuxi Henderchan Industrial Co Ltd
11 yrs
·
5.0
Send Inquiry
High Quality China Manufacturer 2"X3" 3500lbs Adjustable Heavy Duty Trailer Coupler Trailer Coupling Towing Coupler
US$
10.00
-
15.00
500 Pieces
(MOQ)
Adjustable Channel Tongue Heavy Duty Trailer Standard Coupler Trailer Coupling Towing Accessories
US$
5.00
-
10.00
500 Pieces
(MOQ)
Heavy Duty Trailer Accessories Coupler Adjustable Trailer Coupler Towing Coupling
US$
5.00
-
10.00
500 Pieces
(MOQ)
Wholesale Price Adjustable Trailer Coupler Towing Accessories Trailer Coupling a Frame Coupler Towing Accessories
US$
5.00
-
10.00
500 Pieces
(MOQ)
1/4
Shandong Pinzheng Metal Products Co., Ltd.
9 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
Building Construction British Type Standard Scaffolding Drop Forged Steel Angle Adjustable Clamp Swivel Coupler
US$
1.40
-
1.60
2,000 Pieces
(MOQ)
Building Construction Italian Type Scaffolding Drop Forged Steel Angle Adjustable Clamp Double Coupler
US$
1.80
-
2.00
2,000 Pieces
(MOQ)
High Quality Building Construction American Type USA Standard Scaffolding Drop Forged Steel Angle Adjustable Clamp Swivel Coupler
US$
2.20
-
2.40
2,000 Pieces
(MOQ)
Peri Trio Concrete Formwork Bfd Formwork Coupler Bfd Concrete Panel Lock
US$
6.30
-
6.50
2,000 Pieces
(MOQ)
1/4
Ningbo Harsco Machinery Co., Ltd.
Send Inquiry
2-5/16 Inch Hitch Ball Channel-Mount Adjustable Trailer Tongue Coupler
US$
20.00
500 Pieces
(MOQ)
2-5/16" Hitch Ball Channel-Mount Adjustable Trailer coupling Tongue Coupler
US$
10.00
500 Pieces
(MOQ)
Pro Series Gooseneck Hitch Coupler - Adjustable - Round - 2-5/16" Ball - 25,000 lbs
US$
100.00
50 Pieces
(MOQ)
2-5/16"Trailer Adjustable Channel Coupler Adjustable Couplers Channel Mount Coupling
US$
20.00
500 Pieces
(MOQ)
1/4
Chiping Dingli Steel Sleeve Co., Ltd
13 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
One Touch Most Needed Products GB M16 Rebar Coupler for Connection Adjustable Tie Rods for Sale
US$
0.20
-
0.75
500 Pieces
(MOQ)
Steel Adjustable Rebar Coupler for Metal Building Materials12-40mm
US$
0.20
-
0.75
500 Pieces
(MOQ)
Upsetting GB M16 Rebar Coupler for Connection Adjustable Tie Rods for Sale
US$
0.53
100 Pieces
(MOQ)
Bolted Rebar Coupler Steel Manufacturers
US$
0.20
-
0.75
500 Pieces
(MOQ)
1/4
Bythai Scaffolding Co.,Ltd.
Send Inquiry
Building Construction British Standard Scaffolding Drop Forged Steel Angle Adjustable Clamp/Swivel Coupler
US$
0.60
-
1.20
1,000 Pieces
(MOQ)
Drop Forged Beam Coupler Adjustable Beam Clamp
US$
1.00
-
6.00
100 Pieces
(MOQ)
Building Construction Forged Scaffolding Clamp Scaffold Beam Clamps Scaffolding Drop Forged Steel Angle Adjustable Clamp Swivel Coupler
US$
4.50
-
8.50
1,000 Pieces
(MOQ)
Best Selling Heavy Duty Drop Forged Double Swivel Scaffolding Coupler for Scaffolding
US$
4.50
-
8.50
1,000 Pieces
(MOQ)
1/4
Cangzhou Xinlongyi Construction Equipment Co., Ltd
Send Inquiry
Adjustable Design High Strength Customizable Forged Scaffold Double Couplers
US$
0.20
-
1.00
1,000 Pieces
(MOQ)
High Durability Adjustable Design Customizable Galvanized Stamped Scaffold Fastener Coupler
US$
0.30
-
1.00
1,000 Pieces
(MOQ)
Rust-Proof Adjustable Customizable Golden Mild Steel Ladder Clamp
US$
0.60
-
1.00
1,000 Pieces
(MOQ)
Quick Installation Anti-Fall Design Customizable Adjustable Clamp Formwork
US$
3.90
-
5.00
500 Pieces
(MOQ)
1/4
Hengsen Smart Control Technology (Zhejiang) Co., Ltd.
Send Inquiry
Refrigeration Parts Adjustable Quick Coupler
US$
5.50
-
15.00
1,000 Pieces
(MOQ)
Refrigeration R134A Adjustable Manual Brass Quick Coupler for Air Conditioner
US$
4.30
-
4.60
300 Pieces
(MOQ)
Car Air Conditioning Quick Coupler
US$
1.00
-
2.00
500 Pieces
(MOQ)
Factory Direct Selling Hengsen Air Conditioner Part Quick Coupler for Refrigeration Parts
US$
12.70
-
18.42
100 Pieces
(MOQ)
1/4
Qingdao Tsingleader Industry Co., Ltd.
Send Inquiry
Trailer Parts Adjustable Coupler with Bolts & Bracket Capacity 10000lbs and 14000lbs
US$
10.00
-
20.00
1 Piece
(MOQ)
Trailer Parts Heavy Duty Coupler a-Frame Couple Adjustable Coupler with Capacity 12500lbs
US$
10.00
-
20.00
1 Piece
(MOQ)
Trailer Parts Trailer Hitch Pin & Clips Trailer Couplers Locks Swivel Hitch Trailer Pin
US$
1.00
-
4.00
1 Piece
(MOQ)
Trailer Parts Australian Trailer Coupling Fixed Coupling Ring Coupling 3500kg Quick Release 50mm Coupling
US$
10.00
-
20.00
1 Piece
(MOQ)
1/4
Ningbo Beilun Loveyoung Auto Accessories Co., Ltd.
5.0
Send Inquiry
Heavy Duty Steel Adjustable Trailer Coupler Tow Hitch Parts for Traielr
US$
18.50
-
19.00
100 pieces
(MOQ)
2-5/16 Heavy Duty Adjustable Trailer Coupler15000 Lbs Black
US$
18.50
-
19.00
100 pieces
(MOQ)
Loveyoung High Quality Steel 2 Inch Trailer Hitch Coupler with Hitch Cover Lock Pin
US$
4.60
-
5.00
100 pieces
(MOQ)
Hot Sale Tow Hitch Accessories 2 Inch Ball Capacity 3500lbs Straight Trailer Coupler
US$
4.60
-
5.20
50 pieces
(MOQ)
1/4
CHANGSHA XIANGJIA METAL MATERIAL TRADING CO., LTD.
21 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
BS 1139 Building Construction Forged Scaffolding Clamp Scaffold Beam Clamps Scaffolding Drop Forged Steel Angle Adjustable Clamp Swivel Coupler
US$
0.50
-
1.20
100 Pieces
(MOQ)
Vietnam Market Metal Building Material Drop Forged Putlog Coupler Adjustable Galvanized Scaffolding BS1139 Single-Coupler
US$
0.50
-
1.20
100 Pieces
(MOQ)
M 48.6mm 110 Degree Pressed Scaffolding Swivel Clamp Coupler Japan Style
US$
1.20
-
1.50
10,000 Pieces
(MOQ)
BS 1139 Certificate Steel Formwork Forged Scaffolding Clamp Scaffold Board Clamps Swivel Coupler
US$
0.50
-
1.20
100 Pieces
(MOQ)
1/4
Wenling Feichi Electric Appliance Technology Co., Ltd.
Send Inquiry
5 Connecting Adjustable Pivot Adaptor Pressure Washer Pivoting Coupler
US$
0.31
-
0.54
500 Pieces
(MOQ)
5 Angles Quick Connecting Adjustable Pivot Adaptor Pressure Washer Pivoting Coupler
US$
2.00
-
5.00
50 Pieces
(MOQ)
Hot New Products 1/4 Inch Quick Connecting Pivoting Coupler 180 Degree
US$
2.00
-
5.00
50 Pieces
(MOQ)
Coupler Five Levels 1/4" Quick Plug + 1/4" Quick Disconnect Socket for High Pressure Car Washer
US$
2.00
-
5.00
50 Pieces
(MOQ)
1/4
Liangshan Jiuzhou Machinery Manufacturing Co., Ltd.
Manufacturer/Factory & Trading Company
Send Inquiry
Factory Direct Adjustable Trailer Hitch Trailer Coupler Truck Trailer Coupler
US$
300.00
-
497.00
10 Pieces
(MOQ)
High Quality Trailer Parts Adjustable Car Hitch Trailer Hook Tie Rod Coupler
US$
300.00
-
497.00
10 Pieces
(MOQ)
Factory Direct Trailer Parts for Sale Adjustable Trailer Hitch Coupler
US$
300.00
-
497.00
10 Pieces
(MOQ)
Universal Truck Parts Jost Height Adjustable Trailer Hitch Farm Trailer Hitch Trailer Hitch Coupler
US$
299.10
-
496.30
10 Pieces
(MOQ)
1/4
Ningbo Yinzhou KeMing Machinery Manufacturing Co., Ltd.
13 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
Adjustable Heavy Duty Trailer Coupler Supplier
US$
3.20
500 Pieces
(MOQ)
Adjustable Heavy Duty Coupler for Machinery Parts
US$
3.20
500 Pieces
(MOQ)
Adjustable Heavy Duty Coupler for Trailer Parts
US$
3.20
500 Pieces
(MOQ)
Customizable Heavy Duty Trailer Coupler Parts
US$
3.20
500 Pieces
(MOQ)
1/4
Tianjin Tiantai Formwork & Scaffolding Co., Ltd.
8 yrs
·
Trading Company
Send Inquiry
Adjustable Scaffolding Parts Wall Tie Connecting Wall Components Clamp and Coupler Scaffold
US$
3.00
-
6.00
1,000 Pieces
(MOQ)
Scaffolding Coupler Galvanized Steel Pipe Clamp Heavy Duty Construction Scaffolding Fittings
US$
7.50
-
10.40
100 Pieces
(MOQ)
High Strength Steel Cuplock Scaffoldings Couplers for Hotel Building Construction Industrial Use
US$
5.00
1,000 Pieces
(MOQ)
Scaffolding Accessories Swivel Coupler Fixed Clamp Scaffolding Clamp Couplerandamios Galvanizados
US$
0.80
-
2.20
1,000 Pieces
(MOQ)
1/4
1
26
Hot Products
Boat Trailer
Trailer Lock
Boat Trailer Parts
Trailer Coupler
Boat Trailer Axle
Double Axle Cylinder
Small Boat Trailer
Trailer Hitches
Related Manufacturers & Supplier
Galvanized Boat Trailer Factories
Scaffolding Coupler Factories
Double Coupler Factories
Adjustable Height Coupler Factories
Trailer Adjustable Coupler Manufacturers
Trailer For Jet Ski Manufacturers
Custom Jet Ski Trailer Manufacturers
Galvanized Jet Ski Trailer Manufacturers