Listing is for four (4) Service Caster Series #20 swivel caster set with 2 total lock brakes and a 5" diameter by 1-1/4" wide thermoplastic rubber wheels and .845" diameter x 2" length grip ring stems. Supports up to 300 lbs. per caster. When searching for a reliable and durable solution to your IRSG replacement caster needs, consider Service Caster’s Series 20 thermoplastic rubber casters. The Service Caster Series #20 is ideal for light and medium duty material handling, carts, equipment, and shop projects. The zinc plated finish provides durability under any condition, and the soft, quiet and non-marking thermoplastic rubber wheels perform especially well on hard surfaces such as concrete, tile, and wood. They are resistant to water, oil, and grease and will keep you safely moving forward. Mounting options include top plate, bolt hole, grip ring stem, standard and metric threaded stem sizes. Service Caster is unsurpassed in quality, reliability, and excellent customer service. Count on us to move you forward.