This 4" x 1-1/4" polyurethane on plastic standard duty threaded stem caster is durable and easy to roll. Polyurethane wheels are excellent for indoor or outdoor use. The caster is retained with a 1/2-13UNC x 1-1/2" threaded stem. Our 25 Series is an economical lineup of casters and wheels designed for a range of applications with load requirements up to 350 pounds. These casters are available in a variety of size, wheel, fastening and brake options, and features a one-year standard warranty.