2-1/4" Metal Ball Caster with Rubber Tread, Bright Chrome with 5/16" x 1-1/2" Wood (Grip Neck) Stem Capacity: 75 lbs Diameter: 2-1/4" Mounting: Wood (Grip Neck) Stem - 5/16" diameter x 1-1/2" long Finish: Bright Chrome with Rubber Wheel Tread Bearing: Self Lubricating Acetyl Resin Bearing