This product is made of durable, heavy-duty aluminum alloy. These bearings can be tightened or fixed because they have through holes and pre-drilled holesProduct Name: Rotary Table BearingProduct color: silverProduct material: aluminum alloyProduct features: durable, brushed surface treatment, smooth, strongs load-bearingThe package includes: 1 slewing bearing (with lubricating oil above 300 mm)Product size: 200mm (8in), 250mm (10in), 300mm (12in), 350mm (14in), 400mm (16in), 450mm (18in), 500mm (20in), 580mm (23in), optionalNote:Due to the difference in light, angle, and monitor, the color may differ from the picture, please forgive meIf you have any questions or doubts, please feel free to contact us via email, we will provide you with a satisfactory solution in the shortest possible time