Description Size: Bearing inner diameter: Wheel diameter: 40mm / * Thickness: 18mm Installation: simple luggage rollers, without professional instructions, can be installed by yourself, very convenient. Also pay attention to the tightness of the wheel when installing, so that the luggage casters can roll better. Advantages: High quality replacement wheels. Sturdy, quiet, load-bearing, double bearing, flexible rotation. Load: A single suitcase can bear up to 51 kg, without deflection of the phenomenon for safe and reliable use. Cleaning: The replacement suitcase wheels are easy to clean, and the wheels can be removed for cleaning. Buyers need to measure the data of the following suitcase wheels to know what size they are able to roll : 1, Measurement of the original outside diameter of the wheels (wheel size). 2, the inside of the groove width of the measuring wheel ( width of the total installed width). 3, through the length measuring screw (without a nut at both ends). 4, measured by the diameter of the thickness of the tube carrying the width of the bore.