A caster (also known as castor according to some dictionaries is a wheeled device typically mounted to a larger object that enables the relatively easy rolling movement of the object. Casters are essentially housings, that include a wheel and mounting to install the caster to objects (equipment, apparatus, and more). Casters are found virtually everywhere, from office desk chairs to shipyards, and from hospital beds to automotive factories. They range in size from the very small furniture casters to massive industrial casters, and individual load capacities span 100 pounds (45 kg) or less to 100,000 pounds (45 t). Wheel materials include cast iron, plastic, rubber, polyurethane, polyolefin, nylon, thermoplastic rubber, forged steel, stainless steel, aluminum, and more.