Qualcraft 2420 Aluminum Two-Rung Short Body Ladder Jack Many uses, such as, painting siding, window repair, general repair. Takes two to use. For a super quick set-up and tear down, use Qual-Craft aluminum ladder jacks. These tough riveted and welded ladder jacks will work on the inside or outside ladder face. They should be fully decked using an 18" wide platform that comply with OSHA requirements Qual-Craft ladder jacks are adjustable to fit round or "D" rung ladders.