ball transfer unit 1, over 30 different model with different loading capacity 2, ball material steel, nylon, stainless ball transfer unit ModelMain BallSub BallBall Cuploading capacity(kg)RemarkDia(mm)MaterialDia(mm)Materialball upball downBT300-0368B30.18Stainless3.18StainlessCarbon Steel,Hardened,Z/P227807 Drain Holes BT300-0368S30.18Stainless3.18StainlessCarbon Steel,Hardened,Z/P227807 Drain ...