2 x 5 x 2 Stainless Steel Open Ball Bearings Lot of 10 Bearings 2 x 5 x 2 Stainless Steel Open Ball Bearings, SMR52 are made of Stainless Steel, SMR52 is a popular miniature size that could be used in many fishing reels, inner diameter is 2mm, outer diameter is 5mm and width is 2mm.