Listing is for one (1) Service Caster Series #20 swivel caster with a 4" diameter by 1-1/4" wide blue polyurethane wheel capable of supporting 350lbs./caster. When searching for a reliable and durable solution to your caster needs, look no further than the Service Caster Series 20 top plate polyurethane 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, while the non-marking, non-marring polyurethane wheels perform especially well on hard surfaces such as concrete, tile, and wood- rolling on a finely crafted ball bearing design that keeps you moving forward. Service Caster is unsurpassed in quality, reliability, and excellent customer service. Count on us to move you forward.