The Nylon plug for all building applications, it's universal operating principle (knotting or expanding) allows for use in all solid, hollow and board building materials. Thus the UX is the correct choice for unknown base materials. The UX‘s angled connection ridges allow for optimum screw guidance. Serrated anti-rotation locks prevent rotation in the drill hole. This guarantees the greatest possible installation safety. This item can be used in a whole variety of applications including, Hollow block made from lightweight concrete, Cavity floor slabs made of brick, concrete, etc., Perforated sand-lime brick, Solid sand-lime brick, Natural stone, Aerated concrete, just to name a few.... Contact us today for more information about this product.