This is to carry MP5 high across the chest in a military 'port arm' position.
You simply insert your sling center bar of the double eye into the metal clip of MP5...

 

In Africa they put a nail in the wall and hang their G3's using that hole in the clip.
Strange but true.
G3Kurz

 

Stop spreadin those dang Intranets rumors!!!!

 

Hmm,

Maybe I will make space on my coat rack.

Thanks for the info.

 

It's for popping the tab on a beer can so you don't break a fingernail.

 

True dat... it's a bummer to break a good nose pickin' nail.

 

I use it for a keychain charm