The Carrymaster ACT series are medium duty swivel casters with low profile that combine the functions of a caster and a leveler. With twin wheel design, ACT series has an excellent ability to rotate tight corners. ACT series casters come with anti-vibration leveling foot (default NBR nitrile rubber pad, optional urethane pad) that can be easily adjusted by turning a thumb wheel. ACT 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 441lbs to 882lbs per caster and depending upon the load capacity the wheel size range from 50mm to 72mm. The metal frame of ACT series is aluminum diecast with powder coat & zinc galvanized finish. The default wheel is made out of PA6 material in black.