VEVOR Material Lift Winch Stacker, 330lbs Capacity Pallet Truck Dolly, 42.9in Max Lifting Height Manual Winch Stacker, Multifunctional Manual Pallet Truck Stacker with Swivel Casters and Lift Plate

For the Material Lift Winch Stacker 330 lbs Capacity Pallet Truck Dolly 42.9 in Max Lift how many inches do the support legs extend beyond the platform in the lowered position and at the top position.

Does the Material Lift Winch Stacker 330 lbs Capacity Pallet Truck Dolly 42.9 in Max Lift have a mechanism to hold an object that it lifted at the height that I lifted it. If I let go of the crank does it just unwind and the object lifted falls to the floor ( which would be a pretty bad design). I can not see a locking or holding mechanism in the photos.