1. Small and light, easy for installation and reqair, and can be installation on any position.
2. Simple structure, well-organied, pronpt 90 degree turn round, open and close.
3. Small operating torque, simple and light.
4. Flow rate characteristic tend to straight, well regulate.
5. Open and close test over 10, 000 times, long life.
6. Complete seal, noleakage during air testing.
7. Choose different material as parts, fit for kinds of medium.