Listing is for a set of four (4) Service Caster Series #20 stainless steel casters, two (2) swivel 10mm-1.50 X 1-1/2" threaded stem with total lock brake casters and two (2) swivel casters, with 3-1/2” diameter by 1-1/4” wide gray polyurethane wheels. Supports a total weight of 1,200lbs (300lbs/per caster).