Electro Magnetic Pulse. Toss it at anything electronic and you've got yourself a lightshow of death.
In-game description, DL
The EMP Grenade is a gadget in Deadlocked used by Ratchet's combat bots, Merc and Green, or by a player in co-op mode. When used, the grenade can deactivate forcefields, electricity from electrified platforms, and shields from some Landstalkers and 70 millimeter Stalker Turrets (which it also stuns).