You need 6inch-Lock-Swivel-Caster-023 to have your office desk, equipment or even a machine to easily roll them around. Diameter of the caster wheel is a metric standard 150mm that is equal to 5.906" inch with imperial units. Dimensions of the caster wheel is 50mm (1.969" inch). The caster dimensions heightwise is 193mm/7.598" inch. Top Plate is the method of installing the caster to your equipment, the dimensions are 100mm x 115mm with the holes distance of 75mm x 85mm. The caster core is made of Black Cast iron and has a Black Cast iron tire with a low friction Roller bearing. Here come the maximum load that should be applied on every wheel, remember to add safety factor, when calculating the load capacity 617 lb with a Swivel and Center Locking type. The temperature range is -40 to 180 F. Remember, you will have to buy the 6inch-Lock-Swivel-Caster-023 in order to have it :).