Features: Designed with a serrated hexagon washer head, these screws offer not only functionality but also an aesthetic bonus. This design prevents them from falling out, ensure long-term stable and firm fixing effect Installation method: First use 1/2 hammer drill to open the hole, and then directly use the wall anchor installation, suitable for DIY users and professional construction workers Specifications: Material: galvanized steel Color: sliver Size: about 1/2inch x 4inch Package includes: 40 x Concrete screws Notes: Manual measurement, please allow slight errors on size. The color may exist a slight difference due to different screen displays.