Vestil Quick Install Manual Trollies, QIT Series are dependable, easy and safe to use. Trollies are designed to adjust to the width of virtually any S, H, W and M type I-beam. Width is adjusted using a manual screw mechanism. Includes locking ring to prevent trolley width from changing accidentally. Manual screw mechanism may also be tightened to prevent trolley from moving (similar to a Beam Clamp). Each trolley includes four rollers with sealed bearings for long life. A lifting eye is located at the bottom of the trolley for attaching a hoist (hoist not included). All steel construction with durable blue enamel finish.