Service Caster - 12" x 3.5"  Black Pneumatic Rubber Wheel Swivel Caster - 450lbs/Caster Wheel: 12" x 3.5" Pneumatic - Black Capacity: 450 lbs/caster Top Plate Size: 4" x 4.5" Bolt Hole Pattern: 2.625" x 3.625" to 3" x 3" Mounting Height: 13.75"