The Mission First Tactical BattleLink Utility stock is a slide-on stock with accessory mounting provisions (including Garmin GPS in choice of two positions with additional mounting adapter) to replace limited utility original collapsible stock. Its large, pivoting, rear accessed storage compartment is watertight and includes a customizable foam storage block to minimize rattles. The block has a quick access tab to save time getting to what you have stored inside.Two Quick detach Sling mounting points are positioned for optimimum usage. The upper section of the buttstock provides an enhanced cheek weld. There are also provisions for mounting accessories, including a Garmin GPS unit with the proper adapter (sold separately). For guns with the Mil Spec buffer tube assembly. Made in USA