Hit the impulse and your current weapon disappears into a backpack which you throw. You start with 2 empty packs. You can collect up to 20. When you're out, you cannot toss weapons. This is really an extension of the above.
Strategic value is completely different, though.
You can select your weapon1 and toss an empty pack. Looks just like a weapon pack. The Assassin will love this. Raven observer mode. I include this as a tribute to Siege.