16 Inch Caster heavy duty. Tires are 4ply with max psi 30lbs. The frame of this caster is much lager than standard caster from the box stores. The hubs are equipped with ball bearings and grease fittings. Swivel plate turns on a 3 1/2 inch in diameter ring of ball bearing with grease fittings. Caster weighs over 13lbs