... 2) Plastic balls are made of different materials, such as PP,PE, POM, PA,PMMA and so on. The tolerance can ... POM,PA,PMMATrackball,Ball valve,Bearing ball, Roll on ball,and so onHollow ball10mm-100mmPP,PE,HDPERoll on ball,Bearing ball,Ball valve,Floating ball,and so ... onRoll on ball and holder8mm, 10mm,19.05mm,25 ...