【SET INCLUDES】100 Pieces M3.5 x 40mm Quick Fix placo Screws. 【EXCELLENT MATERIAL】Material - Carbon Steel, Threads - Fine Thread, Shank - Pointed, Head - Bugle, Drive - Phillips PH2. The black color of carbon steel screws is the result of a phosphate coating, which is used to help prevent rust. Without the phosphate coating, wet residue from the drywall can cause the screw heads to rust. 【EASY TO INSTALL】Use a Phillips screwdriver (2PH bit), sharp point and fine thread screw firmly connect the two surfaces and the bugle head prevents them from digging into the drywall and stays flush with the surface. 【USE】Drywall screws designed to attach drywall panels to wood or metal, optimized stitch geometry and bugle head can effectively install drywall and steel profiles, versatile screws used in a variety of applications, the screws are thin enough to attach drywall panels to ceilings and wall joists without damaging the materials. 【UNIVERSAL SCREW】Most people prefer to use drywall screws for