This is an anti-slip device that can be used on virtually all exterior hazardous surfaces. It not only has the unique engaging pins on the base, but also on the top. This can be used in areas where there could be clay, diesel or any residue that could compromise the rubber on the base of the ladder. This means that the pins on the top hold the ladder stable. Allows you to do everyday jobs safely such as clearing the gutters, gardening and general household maintenance.