a common Multi-Purpose Articulated Folding Ladder. It’s a robust and extremely versatile option for both professionals and heavy-duty home use. The specification “$4 \times 5\text{M} (5.7\text{M})$” means: $4 \times 5$ (Configuration): The ladder has 4 folding sections, with 5 steps/rungs on each section, giving a total of 20 steps.1 $5.7\text{M}$ (Maximum Length): This is the approximate length when the ladder is fully unfolded into a single, straight extension ladder.2
