Did you catch sight of that little fold-out-machine-gun looking thing in the last Batman: Arkham Knight trailer? Don't worry, Batman hasn't finally dropped his "no kills, just concussions" policy - it's actually a high-tech Disruptor that will mess with enemies without splattering blood all over the street.
In fact, the Disruptor's primary use is actually as the anti-gun. Batman can jam a ne'er-do-well's firearm with a single long-range zap, leaving the thug none the wiser until he pulls the trigger. One more Disruptor shot on the same weapon and it will explode outright, which is a bit less subtle but does make quite a statement.
The Disruptor wouldn't be a proper Bat-Gadget if it just did the one thing, so it can also be used to rig weapon crates to shock enemies, and even to tag vehicles for future Batmobile chases. Keep in mind that the Disruptor starts off with just three charges per encounter, so you'll need to budget them appropriately.
Naturally, you can upgrade the Disruptor along with the rest of your arsenal. You might give it an extra charge per encounter, or even boost its weapon-sabotaging capabilities so that you can make the Arkham Knight's drone tank turrets backfire when they try to blow up your sweet Bat-ride.
You may have also noticed the Batwing makes a brief appearance in the same "All Who Follow You" trailer. Developer Rocksteady plans to expand on its role in Batman: Arkham Knight next, so stay tuned to the same Bat-channel.