1pc 7 Point Spline Drive Socket Key Tool for Spline Locking Lug Nuts - Compatible with 19mm (3/4") and 21mm (13/16") Hex Sockets This listing is for 1 Socket Key Only compatible with 7-sided Spline Lug Nuts Please double check your lug nut before purchasing; this is for 7-sided spline lug nuts, as there are multiple types of tuner locking lug nuts on the market. Compatible with Multiple Socket Sizes: 19mm, 3/4", 21mm, 13/16" Hex Sockets Special coating provides exceptional appearance and corrosion resistance <span class="a-text-bold">Splines: 7</span>-Point <span class="a-text-bold">Color:</span> Black <span class="a-text-bold">Material:</span> Steel <span class="a-text-bold">Process: </span>Heat treatment Please note that this socket is only compatible with tuner style 7-spline lug nuts. Please see other listing for 6-spline socket key. NOT designed to work with standard Hex lug nuts. Perfect as a replacement for a lost or missing socket key. Can be used with both 19mm and 21mm Hex sockets. Standard Hex socket not included