Red Head LDT-3830X Large Diameter Tapcon 3/8-Inch by 3-Inch EnvireX Anchor (50 per Box) Cuts it's Own Threads into Concrete Anchor Bodies are have EnvireX Coating for Outdoor Applications Finished Hex Washer Head, with Anti-Rotation Serrations Anchor is Stamped with a Length Identification Code Use Standard Drill Bits