Kill-O-Watt is an alternate Pack-a-Punch ammo-type found in Call of Duty: Black Ops 4, and it has a chance to be applied to an upgraded weapon when placed in the Pack-A-Punch Machine again. It costs 2500 points initially, but lowers to 1500 after upgrading your weapon 4 times.
Kill-O-Watt ammo has an area of effect stun that can occur on a short cooldown. It will immobilize zombies around the zombie affected and eventually kill them. Zombies affected by Kill-O-Watt's effect will die after about five to ten seconds. Kill-O-Watt ammo is super effective against Water Catalyst zombies, causing them to explode in a high-velocity blast. It is also a necessity in order to complete certain steps in Easter Eggs.