Protect your tools and materials from damage caused by pulling hoses or lines over the sharp edges of roofs or walls. While protecting the project as well. It attatches to the edge of roofs, rungs on a ladder, railings on lifts, as well as fences, framing and most gutters. To switch from ladders, lifts and thicker materials just remove the two scews and turn the bottom plate 180 degrees and put the srcrews back in, now you can hook to the roof edges and other thin materials. just pull out the detent pin put your hose or line in the cradle and put the pin back in. This tool was designed by a coatings company out of necessity. After years of ruining hoses and cords costing hundreds if not thousands a year to replace them, not to mention the damage the lines due when pulled accross a finished product. Best part They were designed and built in the US.