5 / Set. Deluxe Duet twin-wheel casters complement all types of office and home-office furniture. 2" diameter dual wheels provide maximum mobility and smooth quiet rolling on light-duty to medium-duty applications. Use hard wheels on carpeting. Weight rating is 100 lb. per caster. Casters include 7/16" x 7/8" B stems and 3/8" x 1" K stems.