Ergo Grip O-Grip, Zero Angle Precision, Grip, Black, AR Rifles 4022-G2-BK The all-new Gen II ERGO O-Grip features a threaded grip cavity that can be utilized for the storage of a spare battery or small parts with the use of our 4115 End Cap Plug. The advantage of a threaded plug is increased security under recoil and adverse conditions. Like the original O-Grip" the Gen II O-Grip also features built-in channels that can accommodate the installation of a variety of different sized grip bands" increasing the texture and traction based on the shooters needs.