The Werner Level-Master automatic ladder leveler easily attaches to Werner fiberglass and aluminum extension ladders for even support on uneven surfaces, with automatic adjustment up to 8-1/2 inches thanks to the self-leveling design. Each leg automatically slides down to the surface, then locks securely in place. The Level-Master adds 3-3/4-inches of width to your ladder for greater support and longer spanning capability. It will not decrease the duty rating of your ladder, and it includes two levelers for each rail of your ladder, mounting hardware, and instructions.