: Advantages: 1.Every product has a unique Manufacturing Part Number label on the inner package that proves it has been qualified,which include Part Number,Model Number and inspection date information 2.If you have any questions about the item,please provide us the Manufacturing Part Number for checking,your profits will be guaranteed.3.The plate is made of 45 steel, the wheel is made of nylon.4.U groove type wheel is suitable for round tube.5.Apply to industrial machine tool, trolley. Specifications:Material: 45 Steel + NylonColor: BeigeType: U grooveTotal Dimensions: 56 x 41 x 39mm/2.2 x 1.61 x 1.54 inch (L x W x H)Wheel Diameter: 31mm/1.2 inchWheel Width: 25mm/0.98 inchPlate Size: 56 x 32 x 2mm/2.2 x 1.26 x 0.08 inch (L x W x T)Hole Center Distance: 42 x 18mm/Hole Diameter: 6mm/0.24 inchU Groove Width: 19mm/0.75 inchU Groove Depth: 7mm/0.28 inchMax Load: 100kgWeight: 70gAttentions: Each caster's max load is 100kg. But 4 wheels can only load 300kg. It is good to extend the wheel's lifetime. Because there is always uneven road, 4 wheels are not evenly stressed. Package includes:1 x Rigid Wheel