Milwaukee 48-60-5120 Trade Titan Heavy-Duty 6-by-2-Inch Wheel Caster Set Includes two swivel casters with total-lock brakes and two rigid casters Industrial-grade, nonmarking, debris-rejecting round rubber tread for smooth, quiet performance Designed to conquer rough terrain and jobsite environments Load rating of 450 pounds per caster Each caster has 6-by-2-inch wheels and a 4-by-4-1/2 inch top plate