Double brake locks both wheel and swivel rotation with the touch of a toe. Put your entire shop on wheels! Load rating for each caster is 132 lbs. Easy rolling, non-marring, polyurethane tires will not "flat spot" during long periods of remaining stationary. Swivel and wheel ride on ball bearings for smooth rolling and turning. Double brake locks both wheel and swivel rotation with the touch of a toe. Unlike cheaper casters, which only lock the wheel and allow the supported load to move around as the caster rotates on its base, these provide a rock solid base. The 2 1/2" casters are 3-3/8" tall. Plate size is 2-3/8" W x 2-7/8" L. Distance between holes is 1-5/8" x 2-1/8" center to center.