SFR2-5ZZ Flanged Stainless Steel Ceramic Ball Bearing Quality: ABEC-5 3.175mm x 7.938mm x 3.570mm SFR2-5ZZ Flanged Stainless Ball Bearing, Bearing is made of Stainless Steel, bearing is metal shielded from both sides, inner diameter is 3.175mm, outer diameter is 7.938mm and width is 3.570mm.