The Carrymaster ACM series are medium duty swivel casters with either one wide wheel or a twin wheels. ACM series come in two models, one with a break (break type) or the other with twin wheels (allows better rotation). ACM series are made only in plate/flange (F type). The load capacity ranges from 1,764lbs to 2,205lbs per caster and the wheel size range from 50mm to 72mm. The metal frame of ALC series is aluminum diecast with powder coat & zinc galvanized ivory color finish. The default wheel is made out of Polyurethane with bearings (PA6 material, Black) and some models can be modified with MC Nylon(Ivory or Blue) or Antistatic Polyurethane(with bearings, Ivory).