... stiffness/precision 3.Easily install, long life Full complement cylindrical roller bearings:double row full complement cylindrical roller bearings NNF design Features ... , C4, C56,Material: AISI52100, AISI440C, AISI304, AISI316, Ceramic7,Retainer: PTFE, Nylon, PEEK Or Stainless Steel Model No.1) N202 - N248, N303 ...