Labor saving spanner adopts high effect planet shifts as main transmission. Its characteristic is small volume, light wieght, because of large shifts, input little power can be brought large output power, it's made of alloy steel and heat treatment outside, solidity and well use. The outside is polishedand plated plstic. It has well handle. It is widely used in ammembling different kinds of camion tyres. It is the necesarily tools for repairmen and drivers.