4inch-Lock-Swivel-Caster-019 is a wheel caster, which is the shortcut of installing wheels on a hospital bed, or any objexct needed to be moved. This caster is rolled on a wheel that has 100mm diameter/3.937" inch inches. The thickness of the wheel is 75mm or 2.953" inch. The Caster with the wheel from end to end is 165mm = 6.496" inch. Top Plate is the method of installing the caster to your equipment, the dimensions are 200mm x 153mm Top Plate: 14mm+housing: 10mm with the holes distance of 160mm x 90mm. The Precision double ball bearing design will enable the Cast iron polyurethane tire to roll easily with a core made of Cast iron polyurethane. Each caster will carry the load of 2205 lb and is Swivel and Upper Locking type. Temperature range = -40 to 180 F. Remember, you will have to buy the 4inch-Lock-Swivel-Caster-019 in order to have it :).