This 5" x 1-1/4" polyurethane on plastic premium 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 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 universal.