The ERGO 2 AR Grip is uniquely designed to allow installation on both .556 and .308 AR/M4 lower receivers without a need for spacer inserts. The A2 sized inner cavity is compatible with many accessories available on the market. Features ergonomic finger grooves and integrated rear upper extension web support for the web of your hand. Superior SUREGRIP™ texture improves weapon control, even while wearing gloves. Virtually impervious to oils and solvents.