... :ISO9001:2000 certificate 2.Large sales make our prices super low. high precision bearing,ball bearings,roller bearings:A: Inner Ring Bore Diameter from ... Life.E: Low noise and low vibration: Z1, Z2, Z3,V1,V2.F: Raw Material: Gcr15 Chrome Steel, Stainless Steel AISI440C, Ceramic Si3N4. high precision bearing