Designed for extra heavy loads, DuraGlide Wheels feature 1 in. tread of dynamically responsive polyurethane molded to heavy-duty cast iron core. Thick tread minimizes heat stress on bond line and lowers internal stresses of material. Wheels are also less susceptible to damaging UV rays and essentially impervious to moisture. Available in 6, 8, 10, and 12 in. diameters with maintenance-free double sealed precision ball bearings, DuraGlide Wheels are suited for moist or outdoor applications.