210 Pieces O-Rings Assortment, 7 Common sizes 7 Commonly used sizes Oil resistant rubber construction Comes assorted in storage case 210 pieces Sizes (30 Pieces in each size): 1/4" X 3/8", 5/16" X 7/16", 3/8" X 9/16", 1/2" X 11/16", 5/8" X 13/16", 11/16" X 7/8", 3/4 X 15/16"