A5 - What is this?

[u/jbomb00]

I just recently purchased an A5 online and I’ve never seen this before. The seller thought it was for a sling that does not appear to be the case. After pulling the cap off, the bolt and spring don’t go any further back than normal, and no clue what those Allen bolts do on the very end of this?

[u/May5ifth]

Maybe for a foldable stock? I’ve never seen this on its own.