... Them material is PP or HDPE The floating ball is a kind of surface covering ball.It has the gravity and stability.The ... floating ball side and side overlap,the coverage efficiency ... ,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 ...