The Carrymaster AC series are light to heavy-duty swivel casters that combine the functions of a caster and a leveler. AC series casters are equipped with anti-vibration leveling pad that can be easily adjusted by turning a thumbwheel or a screw nut. AC series comes in two mounting types, one with a stem (S type) or the other with a plate/flange (F type). The load capacity ranges from 110lbs to 3,307lbs per caster and depending upon the load capacity the wheel size range from 42mm to 92mm. The metal frame of AC series is aluminum diecast with powder coat & zinc galvanized finish. The default finish color is ivory and some models come in optional black color. The default wheel is made out of Polyurethane (PA6 material, Black) and some models can be modified with MC Nylon (Ivory or Blue) or Antistatic Polyurethane(with bearings, Ivory).