What harness connection is this

[Rogue]

Found on the drivers side in the engine bay along the fender:

[AndrewBird]

That is an auxiliary fuse box to be able to add aftermarket accessories. It clips into the little rails on the side/end of the fuse box. Should have a little plastic lid for it.

[Rogue]

Ahh ok, that picture is not mine, but mine was cracked and electrical taped up and hanging, so I had no way to identify it...