Polypropylene hollow ball 1)Various colors and materials can available 2)Mainly used in water treatment 3)Good quality Shangyu Hongda Plastics Industry ... ,PA,PMMATrackball,Ball valve,Bearing ball, Roll on ball,and so onHollow ball9.5mm-100mmPP,PE,HDPERoll on ball,Bearing ball,Ball valve,Floating ball,and so ... name is Jane,welcome to chat with me. Polypropylene Hollow Ball For Water Treatment