Door and board lifters are operated by foot, leaving your hands free. Putting pressure on the foot pad lifts the lift shelf, which will raise whatever sheet material is rested on it. They sometimes have a non-slip surface so your foot is more secure on the pad.
The small shelf at the end of door and board lifters supports the sheet material you’re lifting. The wider the shelf the more stable the support should be. The width of the shelf will determine the thickness of sheets they can be used with. They often have a lip which supports the sheet in place while it’s lifted.
The pivot point is the part of the lifter which remains on the floor. Some pivot points on door and board lifters are designed to remain in one place, some can roll and some swivel, for easier adjustments when in use.