AccuWheel KEY-EX6SPCB 6 Point Spline Drive Small Diameter Lug Nut Key - 3/4" and 13/16" Hex Drive - Works with Gorilla SD Small Diameter Lug Nuts (1921SDKEY) Spline key for AccuWheel Black Spline Lug Nuts. Size on 7/16", 12X1.25, 12X1.50, 1/2". Works with Gorilla brand SD Lug Nuts (1921SDKEY) For use with small diameter 6 spline lug nuts Dual hex sizes 3/4" and 13/16" Cold forged then heat treated for exceptional strength