... as PP,PE,ABS,POM,PA, PMMA,and the toleranve can be 0.01mm.2.hollow balls are ... mainly used in the cosmetic packaging ,such as perfume bottles and deodorant ... balls are mainly used in the industry of bearing.4.Function: the roll on bottles are used for body lotion ... cosmetic package,industrial ,track ball,and so on plastic roll on bottle 30ml--180ml PP,HDPE,PE cosmetic package ...