SFR144ZZ Flanged Stainless Steel Ceramic Ball Bearing Quality: ABEC-5 3.175mm x 6.350mm x 2.780mm SFR144ZZ 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 6.350mm and width is 2.780mm.