Bigger and heavier for most aluminum and fibreglass ladders, from Type 3 to Type 1 AA. Made for professionals and perfect for the everyday handyman. The Ladder-Aide is the quickest, easiest, and safest way to use your extension and combination ladders on stairs. It's a compact and portable unit that doesn't require a permanent installation on your ladder, it can easily be moved from stair to stair, and can be used with a variety of ladders. With an anti-skid surface and micro-adjustable height (to within 1/8 inches), it creates a stable, level base for use on stairways. Its rugged construction of high-grade aluminum and steel and heavy-duty design mean it's built to last.