The M320A1 was originally made by H&K. It is a 40mm grenade launcher that has been seen on M4s, G36s and as a standalone weapon system. Capco got the contract to manufacture US made M320A1 Grenade Launchers.

The H&K AG-C/EGLM is their designation for their 40mm grenade launcher. @Steve_MP5  has an airsoft replica mounted to his Walther Umarex .22LR G36.

Here is a photo I took at GSL Technology of their H&K AG-C/EGLM.

Th M320A1 is the variant for the US Military.  While it is typically made by H&K, the US Government often prefers US manufacturers just to simplify logistics. This way if something happens to H&K, the  Government can continue to acquire their M320 launchers.

Photo from Wikipedia

Above you can see the M320A1 mounted to an M4 with a PSQ-18 grenade launcher laser sight.

The following photos were shared but the sender wishes to remain anonymous.

The Capco US Made M320A1 do not come with the stocks nor the rear pressure pad. You can see the H&K has the pressure pad just above the grip. While the Capco version does not.

H&K M320A1 on the Left. Capco M320A1 on the right

The M320A1 can use a PSQ-18 laser sight and you can see where the plug stick up on the H&K M320A1 on the left. The PSQ-18 attaches to a side rail that replaces the factory leaf sight.

Below is the M4 mount for the M320A1. You can see where the mounts would fit in the photo above.

Below is one of my PSQ-18 laser sights. The plug receptacle is directly underneath the laser when it is mounted. Which appears to match up to the position of the pressure pad plug you see in the photo above.

You can see the marking variations between the Capco US made M320A1 and the H&K made M320A1.

The muzzle end of the Capco M320 barrel seems a little different than the H&K barrel.

The Capco M320 can accept the H&K stock.

Below is what was sent as a complete package from Capco. 

Unfortunately these are for contract only. So FFL07/SOT do not ask, you can’t have any.