Split drive anchor is also called concrete split drive anchor. It's made of grade 2 carbon steel with a zinc coating. The anchor is a one piece anchor. On the working end, there is a split-type expansion mechanism. When the anchor is driven into the hole, the expansion mechanism compresses and produces the friction against the hole. There are three head styles: mushroom, countersunk and duplex. The anchor is suitable used in solid concrete, grout-filled block and stone. But it is not recommended for hollow base material. This anchor is suited for permanent, tamper-proof installation. It is suitable for light duty. The anchor is only available in a 1/4" diameter.