"Trolley is dependable, easy and safe to use. Flange Width in. 3-7 1/2, Includes Sealed ball bearing wheels, Material Type Steel, Capacity lbs. 6,000. 10.375in. headroom Width is adjusted with manual screw mechanism Locking ring prevents trolley width from changing accidentally Manual screw mechanism may also be tightened to prevent trolley from moving similar to a Beam Clamp Includes four smooth rollers with sealed bearings for long life Lifting eye is located at the bottom of the trolley for attaching a hoist sold separately Painted finish"