The Astro Tools 71021L 21mm (13/16") Lug Nut Drum Socket - Impact Torque Multiplying Thin Wall Socket is the market's first thin wall deep torque multiplying socket, specifically developed to not lose any torque advantage over our short drum sockets but allows for use on lug nuts in addition to stubborn applications like crank bolts. The hollow drum design multiplies the torque of your ½” impact wrench greater than solid and flywheel style weighted sockets. Upgrade your mid-size impact into a high torque or take your high torque to levels not available in the power tool market with the simple attachment of a socket. This tool works with both air and cordless ½” impact wrenches.