Application - Replacement wheels for suitcases, trolleys or inline skates. When the old wheels are damaged, our replacement casters are a more economical solution to extend the life of your suitcase because you don't need to buy a new travel bag. The wheels are made of high quality material, so they can bear a lot of weight. With more stable and wear-resistant bearings, the wheels roll smoothly and quietly and work well in the trunk. Assembly - Easy to install. First, remove the original wheel bar with a hacksaw or other device, and then install it with the included replacement casters. Specifications: Wheel outer diameter: 45mm. Bearing inner diameter: 18mm Note: The data are all measured manually. Due to the difference in light and display, please allow an error of 1-3 cm. Please refer to the actual object received.