Qualcraft Portable jack suitable for use with: 1-1/2 x 3-1/5.1 cm fir poles or 2.5 cm OD steel tube, malleable iron, powder coated, red, for lifting walls, beams and tightening and real flooring. Easy to use and economical. Made from durable malleable cast iron. Designed for use with 1-1/5.1 cm x 3-1/5.1 cm (2 x 4) pine poles. Used to lift walls and beams, build decks, or to tighten and maintain real floor coverings. Capacity: 1.00 kg. When used in conjunction with poles, made of clear, straight grained fir wood, free from all knots or defects.