Sonic flat double ring wrenches or often known as box-end wrenches provide a 12-point design on each end. Each end has a very slight bend or offset, allowing the body to rise about the fastener plane for knuckle clearance. Sonic wrenches are made from tough and durable Chrome Vanadium steel for a of use and resistance to rust and corrosion. Furthermore, these wrenches are backed by the Sonic Tools Warranty.