The Wall Jack is used to raise walls and beams and tighten flooring and decking. Made of heavy duty, malleable cast iron, the wall jack rides up and down on a 2-by-4-foot pole, working like a car jack for dozens of construction uses. To lift walls and beams insert a length of ¾ inch (OD) pipe (not included) to act as a lever. The Wall jack has a capacity of 1,000 pounds with the use of a 2x4 (actual measurement is 1½" by 3½") made of clear, straight-grained fir wood, free of knots and defects. The jack is intended to meet OSHA safety regulations when instructions are carefully followed. The Wind Hook Accessory Kit provides a complete wall lifting system and can be purchased separately and includes base plate and wind hook cable assembly.