German "D" Ring Securing Device.
Here we have a very useful lockable hinged device suited to securing through the grommet rings of a kit bag.
Extremely robust and should last a lifetime.
....oh, and here's some breaking news from one of our customers (Mr. S.J.L) who's recently received a couple of these via our mail order system....
"Got to say, those "D" rings are AWESOME ! Although you have gone to the trouble of putting the sizes on the page very clearly, I didn't even look at it, so when they arrived I was a little (pleasantly) surprised.