... > Material:QT500-7 Ball Bearing Slewing Ring:1>Size:400-1300 Slewing Ring2>Certi: ISO/TS169493> Ball Bearing Slewing Ring for trailers & tractors 4> Material ... bucket and so on . Our main spare parts are track roller,top roller,sprocket,track link ,bolt & nut, bucket ,teeth ,adaptor,muffler ...