Industrial extension ladder. 28-ft. Made of aluminum. CSA Grade 1. Heavy-duty, 3-in. aluminum side rails. Serrated "D" shaped rungs for comfort and safety. 15-in. wide extension section with 17-in. wide base section for extra stability. Heavy-Duty, self-levelling, swivel feet are rubber-capped to prevent slippage. Gravity-fed locks ensure safe set-up every time. Yellow, protective end caps are non-marring and impact-resistant, providing durability and a longer life to rails.