3" Metal Ball Caster with Rubber Tread, Windsor Antique, with 1-1/2" x 1-1/2" Top Plate Capacity: 100 lbs Diameter: 3" Mounting: Top Plate - 1-1/2" wide x 1-1/2" long Finish: Windsor Antique with Rubber Tread Bearing: Self Lubricating Acetyl Resin Bearing