... Basic data (Q Series): The single-row four points contact ball Slewing Bearing is composed of 2 seat-rings.It features ... ,A.normal7--precision gradeHigh precision,without G.normal Single-row ball,bigger module,outer gear,Outer ring with installation screw holes ... installation bolt holes,Dia.of track center 1250mm,Dia.of ball 40mmOEM supplier for Excavator for your reference, nice quality R260LC ...