This is the plug for the storage compartment in the front of the AGP Butt Stock. If you have broken your End Cap here you can purchase a replacement.
AGP Folding Stocks come preassembled with an End Cap, so you don't need to purchase one unless you want a spare.
AGP Arms AR-15
B (Submitted on 29th May 2016)
Bought an extra one if the original broke. Took me a while to figure out where it actually went and now I'm glad that I got an extra. It's a nice little storage spot in the stock!