3.5 x 7 x 2.5 Shielded Ball Bearing One Bearing 3.5 x 7 x 2.5 Shielded Ball Bearing, Bearing is made of Chrome Steel, Bearing has 2 Metal Shield to protect the bearing from dust or any possible contamination, inner diameter is 3.5mm, outer diameter is 7mm and width is 2.5mm.