LL-STB-1 levelers are quick and easy to install. (In fact, they can be installed with simple tools in less than 15 minutes.) If you prefer, they can be pre-installed at the ladder factory, or professionally installed by local ladder dealers and service companies, such as Advanced Ladders, Batavia Services, Inc., Industrial Ladder, Nationwide Ladders and Ladder Doctor (all specialists in serving utility companies). You can even have your Levelers pre-installed on the ladders you order (see above). With our ladder levelers, you can give your ladders sure footing in nearly any situation - in less than 5 seconds! Note: The LL-STB-1 is approved for installation on ladders up to and including Type 1AA (375 lb) duty ratings. All hardware and instructions for mounting the LL-STB-1 are included.