bicycle metal ball cage

ball retainers

1..size:1/4"*9A 1/4" x 6/7/9/11, 3/16"x6/7/7/15, 5/32"x6/7/14/16/20/21/22, 5/16" x7/9/2 
2.good quality and reasonable price

3.ball retainers are mainly used as bicycle parts.

 steel ball