... Bearing for all types of excavators Single-row ball slewing ring Basic data (Q Series): The single-row four points contact ball Slewing Bearing ... without ,A.normal7--precision gradeHigh precision,without G.normal Single-row ball,bigger module,outer gear,Outer ring with installation screw ... 3R305R280LCR305LC-7R450LC-7R55-7R130R550-3R225-7R215-7 Excavator slew bearing for Single-row ball slewing ring