Geared Trolleys feature lifetime lubricated & double sealed ball bearings. They are used on straight or curved track and adjustable to fit various size wide flange & I-beams. Geared trolleys provide a convenient means to suspend chain hoists from an overhead beam and provide horizontal travel. They use a hand chain to drive the trolley along the beam. These are designed to fit I beam flanges from 1-3/4″ up to 7″.