Jervis Webb Beam Trolley With Side Guide Rollers. Industrial Grade 500 Pound Capacity. Conveyor Trolley For I-Beams. Rugged Cast Iron body construction I Beam Trolley -- Industrial grade Made in the USA by Jervis B Webb, the "gold standard" for heavy duty conveyor components Side guide rollers ensure trolley glides smoothly, can traverse curves and prevent unnecessary wear on track Webb hand push trolleys also available in 3/4 ton, 1 ton and 2 ton models Adapts to 3" and 4" tall I-beams (measure from top flange to bottom flange)