The Tactical Deluxe "OS" Grip is Ergo's best-selling Tactical Deluxe Grip with a 5-degree more vertical angle. It has a thinner beaver tail than the Tactical Deluxe Grip (4045) and fits AR-15s. This grip features the same hand-filling palm swells for both left and right-handed shooters as our standard Tactical Deluxe (TDX). RSR - GFKN-1911G-040221