... certificate 2.Large sales make our prices super low. high precision bearing,ball bearings,roller bearings:A: Inner Ring Bore Diameter ... , RZ, 2RZ, Z, ZZ, N, M are all available.D: Precision Grade: P0, P6, P5, P4 are all available,EMQ motor ... Material: Gcr15 Chrome Steel, Stainless Steel AISI440C, Ceramic Si3N4. high precision bearing