Wrenches are generally accompanied by a variety of socket head and swing handle, extension bar, universal joint, rotary tool joints, elbows, etc. to handle nested hexagonal nut. Socket wrench hexagon socket head is a concave cylindrical; wrenches are typically made of carbon steel or alloy steel, wrench head having a predetermined hardness, middle and the handle portion is resilient. http://www.hbbtglj.com/tzbs/