Industrial grade 6 in. x 2 in. rubber casters with total lock brakes. Non-marking, round rubber tread for smooth, quiet performance. Includes two (2) Swivel Casters with Total Lock Brake and two (2) Rigid Casters. Load rating of 450 lbs. per caster. Due to prolonged, heavy use some components may need to be replaced. Use only Milwaukee specified replacement parts to achieve maximum life and performance from your Milwaukee tool.