The Vevor manual trolley assembly roller set is designed for 1-5/8" wide and 1-5/8" tall or taller strut channels, making installation quick and secure without adjustment. Built from Q235 steel with a galvanized carbon steel construction, it supports loads up to 1,100 lbs for demanding lifting and material handling tasks. Rubber-sealed dual bearings help the rollers move smoothly and steadily while reducing sticking and rolling resistance. This 4-piece set is suitable for garage engine lifting, warehouse material transport, workshop equipment repositioning, and assembly line support.