A sleeve anchor is a type of concrete anchor that consists of a threaded wedge and an expansion element. The assembly is inserted into a pre-drilled hole in the concrete, and then a nut its tightened on the threaded wedge causing the sleeve to expand and create a secure bond with the concrete. Sleeve anchors are often used in applications where a strong and reliable anchor is needed for securing objects to concrete structures. They are available in various sizes and materials, such as steel, stainless steel, and zinc-plated steel.