1.More shock absorption, and greater repair ability for errors of eccentricity, errors of angularity and errors of end-play
2.Superior lubricate self -motion because of industrial plastic and metal parts
3.Outer cover is made by mold so that is easy for manufacture procedure, low cost
4.Using temperature range -20-+80
Assembling and repair is very easy, Can be used in water voltage pump, lubricate