The fischer Plastic Plug incorporates many of the design features of the nylon S plug. The difference in material makes it a more economical alternative in some circumstances. Advantages of the design include anti-rotation lugs. Expansion occurs at the base not the top preventing the plug from splitting tiles or render. The single slot allows you to choose the direction of expansion, which can be important when working close to an edge. The plugs work in many substrates and grip wonderfully; suitable for use in concrete, brickwork, stone and blockwork.