Detailed Product Description carbon product1.ISO 9001;2000 certiicate,EMQ quality2.OEM experience,large sales make low prices3.Raw Material-- low carbon or high carbon4.Precision Grade--P0,P6,P5,,, ,,,5.Vibration:Z1,Z2, Z3,V1,V2,V36.Styles:OPEN,Z,ZZ,RS,2RS....7.OEM service