This 4-inch caster set is perfect for your material handling needs. The bright zinc-plated finish gives it a sleek look and the polyurethane on polyolefin wheel type ensures durability. The set includes (2) swivel casters and (2) swivel casters with posi lock brakes, allowing for easy maneuverability and secure positioning. With a capacity of 1400lbs, these casters can handle heavy loads and the ball bearing wheel and wheel bearing provide smooth movement. The mounting type is a bolt hole and the mounting height is 5-1/8". The tread width is 1.25" and the maximum temperature it can handle is 180 degrees Fahrenheit. This model, RG4, is ideal for use in various industries and settings.