Upgraded Accessories: The material is environmentally friendly PU material and the bearing is carbon steel. SUPERIOR MATERIAL: Made of environmentally friendly PU and carbon steel, with wear-resistant and noise-reducing wheel, providing you with a quiet and convenient life. SIZE: The size of the luggage replacement wheels is replacement wheel OD: 50mm; wheel width: 18mm; The inner diameter of the center bearing is 6mm. Please check the size carefully before placing the order. EASY INSTALLATION: You just need to remove the wheel with a hacksaw at the gap, then put the new ones with the included accessories. Application: The luggage wheel replacement kit is suitable for suitcase wheels, swivel casters, roller skate wheels, etc. Color: Black Material: PU + carbon steel Package Contents: 4 x Luggage Suitcase Replacement Wheels 4 x Axles and Screws 4 x Screw Wrenches 8 x Carbon Steel Bearings 8 x Gasket Only the above package content, other products are not included. Note: Light reflection