The retrofit attachment functions as a level support base across stairs. It is compact and portable, versatile and fast to set up, plus it’s micro-adjustable to match stair riser height. Ladder levellers and leg extenders make ladders heavier and can be annoying to carry around. Ladder-Aide fits any straight extension or telescopic ladder (but not for use with step-ladders). The original model fits a ladder with a maximum 19-in. wide ladder base and 4-1/2-in. feet. The larger Ladder-Aide Pro fits a ladder with a 22-in. base and 7-1/2-in. feet. Visit ladder-aide.com.