This is a very common system for holding clears or vinyl covers to a surface or each other. It consists of a socket and clinch plate (2 pieces). You need to put a small (5mm) hole in the clear or canvas, or vinyl cover. You then press the socket (with the spring clip) through the material over the hole. The teeth on the socket should penetrate the material. You place the clinch plate so the teeth go into the slots in the plate. Bend them and flatten them on a hard surface to set. The stud is screwed into a timber or fibreglass surface where you want the cover to be anchored.As both fasteners are only nickel plated steel, we recommend that you keep them protected with a film of Vaseline or some other proprietary product.