Steelex 6in Black Rubber Swivel Caster Plate Mount. They are extremely quiet offer low maintenance come in a wide range of sizes and are very affordable. The combination of shielded steel hub and tire configuration make these an excellent choice for the metalworking shop where they excel in maneuvering over and around metal scraps. These black rubber swivel casters are 10" have a 5-1/4" x 4-1/4" plate and 600 lbs. capacity. Package Contents: Steelex Rubber Swivel Caster Plate Mount Steelex D2540 6in Black Rubber Swivel Caster Plate Mount