This 4" x 1-1/4" flat tread thermoplastic rubber standard duty threaded stem caster with total lock brake is quiet and smooth rolling. Thermoplastic rubber wheels are floor protective and easy to start. 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.