These Forgefix Rimmed Expansion Wall Plugs are made from 100% Nylon. They rest on the surface of the base material and are particularly useful when the depth of the base material is not known. Sprung anti-spin fins provide a two-way lock, preventing spinning and loosening from overhead applications. Due to the precise two-way expansion, the plugs are suitable for close to edge applications. APPLICATION: Ideal for both lightweight and medium-duty fixing applications. Often used for satellite dish installation. Suitable for all types of threaded screws, including multi-purpose, general purpose, coach screws etc. Not suitable for machine screw threads.