1) The housing is
made of plastic / aluminum / zinc / pressed steel
material
according to customers' requirements
2) The rollers outer ring is made of plastic
materials (POM, PP, PA, nylon)
or metal material, with excellent surface for sliding windows
and doors
3) The inner ring is made of carbon steel with zinc
plated, with excellent
resistance to corrosion capacity
4) The roller set with long life performance
