2-1/4" Metal Ball Caster with Rubber Tread, Bright Brass, with 1-3/16" x 2" Top Plate Capacity: 75 lbs Diameter: 2-1/4" Mounting: Top Plate - 1-3/16" wide x 2" long Finish: Bright Brass with Rubber Wheel Tread Bearing: Self Lubricating Acetyl Resin Bearing