Double row ball bearing 1.High precision & quality 2.ISO 9001 certified 3.Low noise,Stable in chemical 4.Single & double row Double row ball bearingMaterial: chrome steel ... ,6300Series,6700Series,16000Series,6800Series,6900Series,1600Series,1600Series, wider Series, Inch R series,MR Series,RLS series,RMS seriesSpecification:1) Open, Z, ZZ, RZ,2RZ ...