It's a bomb. You throw it, and it morphs into an imitation of the next item in your inventory. When some hapless scavenger tries to shoot you with it, it blows up in their face with the power of a Coalition hand grenade. If you have nothing else in your inventory, it defaults to the form of a ronin glock.
The imitated item always has a mass of 5.5555 kg, so you can use CC48's advanced scanner to tell if a dropped device is one.
And if I'm reading the DRL twitter correctly, those scanners will become official content later, so that's neat.

This gif demonstrates the explosion. Please disregard the bullet that also flew out of the explosion, I fixed that and made it so the imitation never fires its original projectile.

I imagine this will be most fun to use for those who play lots of multiplayer, but it's still fun when used against bots too. Editing activities to give it to bots might be cool, too.
I planned to do some other stuff with this, but didn't bother. Maybe later.
Grif helped with the script a bit, with the idea of checking ID numbers to check if something still exists.
[we found that if something no longer exists, the ID is 255. This is the simplest way to avoid a crash when trying to reference something that might disappear/break that I know of.]

So cool. So very, very cool. A bit tough to get the AI to pick the damned thing up, but it's still really cool.

Destroying all other enemy-held or dropped weapons you see will definitely help with them falling into the trap, with the triple purposes of making them need to scavenge, removing their other scavenging options, and keeping the imitation weapons in-play, rather than settling to terrain due to the device limit.

Revenge!
I picked up the AK-47 outside the shooting range in the tutorial bunker and threw this one in it's place.
Then I went away and waited until the dummy tried to escape. He picked up the fake AK-47, aimed at one of the doors of the range and BOOM! He was gone!

Very good mod sir.

That's very creative, take psychological advance on enemies and drop some of them around the fields...
I miss more sabotage and trap items to spread around the map, like hunting clamps or wire perimeter (+18)

Why not add a bigger explosion for higher prices and heavier erm "Fake guns??" Cool mod I loved having a trap in the field to throw my enemy in for a surprise

Didn't tell my friend about this mod in local play:

'Hah, you dropped your AutoCannon, mine now'
*Explodes*
'God damn it...'