... PE, POM, PA,PMMA and so on. The tolerance can be 0.01mm with good surface and precision.3) Our products ... 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 ... are good in quality with low prices.We look forward to receiving your order! 9mm plastic solid ball with roll on