TEKTON 3/8 inch drive 12-point sockets are an exact fit for double hex fasteners and also work with hex and square shapes. They're designed to grip the sides and not the corners of the fastener heads. which prevents round-off. Their extended length allows the deep socket to fit over long fasteners and reach into recessed areas. The large. die-stamped markings are permanently impressed into the material and optimized for readability.