1.81 in. high formed steel channel. Frame reinforced with 16 gauge steel angle welded to the inside of the channel. 14 gauge steel tubing capped at the point of floor. Contact with high impact plastic glides. Equipped with drop in couplings. Units of same or different heights joined together. Load bearing capacity: 200 lbs.. Built in latch secures stages to dolly. Holds six stages. Warranty: 5 years. Made from steel. Assembly Instructions.