3 Story Portable Steel Chain Fire Escape Ladder - 25 ft with WIDER HOOK for thicker walls! * Chain tension tested to 1000 pounds in weight, window width minimum 13" * Suitable for most windows 13" wide + and for wall thickness between 9" and 14" deep * Stand offs incl to keep ladder away from building-Adjust stand off placement to avoid windows below * Ladders can be used more than once allowing for fire drills