This 3-1/2" x 1-1/4" polyurethane on plastic premium standard duty threaded stem caster with total lock brake 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 22 Series premium standard duty threaded stem casters feature high quality, durable and quiet wheels and optional total lock brakes. A variety of mounting options are available as well. High quality wheels feature precision ball bearings and optional delrin bearings, making these casters versatile and universale.