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 ft pole working like a car jack for dozens of construction uses. To lift walls and beams insert a length of 3/4 in (OD) pipe (not included) to act as a lever. The wall jack has a capacity of 1000 lb with the use of a 2 x 4 (actual measurement is 1-1/2 in by 3-1/2 in) 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.