Men, materials and tools are smoothly raised with positive action foot pedal and easily lowered by turning a crank. Pump jack operates on your "upright" (post unit) made of two straight 2 x 4's. Uprights can be on uneven ground and in narrow spaces. Make sure, however, that ground is firm. For added safety, place 2 x 8 x 8" plate under post. Plate should be toe-nailed to upright. System will allow adjustment to a variety of corners, angles and placements up to 30' in height and creates a 24" standing platform.