Listing is for a set of four (4) Service Caster Series #20 1-1/2" expanding stem stainless steel swivel casters, two (2) with top locking brakes, with 3-1/2" diameter by 1-1/4" wide blue polyurethane wheels capable of supporting a total weight of 1,000 lbs. (250 lbs./caster).When searching for a reliable and durable solution to your caster needs, look no further than the Service Caster Series 20 stainless steel expanding stem polyurethane wheel casters. The Series #20 features an innovative expanding stem that can easily adapt to the inside diameter of the opening, allowing for a secure fit in round or square tubes. Simply tighten the topmost knurled nut to compress the rubber for a snug fit. For added security, further compress the rubber with a wrench via the nut under the swivel raceway. The luxuriously polished stainless steel finish resists rust and corrosion in indoor or outdoor applications where moisture is a factor, while the non-marking, non-marring polyurethane wheels perform especially well on hard surfaces such as concrete, tile, and wood. This versatile caster is ideal for work tables, shop projects, or any equipment with round or square tube legs.Service Caster is unsurpassed in quality, reliability, and excellent customer service. Count on us to move you forward.