[Size] - Wheel Size: 30x11mm / 1.18x0.43 Inch(DxTHK); Thread Size: M6 Size: 30x11mm(ODxTHK); U Groove Width: 6mm / 0.23 Inch [Material] - The bearing roller is made of nylon, and the threaded rod is made of metal [DIY Gadgets] - Slide smoothly and…