Differential pressure controller

The differential pressure controller is a quest item that can be found and obtained by the Courier in Fallout: New Vegas.

Characteristics
Differential pressure controllers are used for the repairing of air filtration systems, and is a highly sought after commodity within the Brotherhood of Steel's hidden bunker in Hidden Valley, for use in the Still in the Dark quest.

Locations
Vault 11 - the differential pressure controller is located in one of the first rooms one may encounter on the lowest level of the vault, which has been flooded with water (note that there are air pockets near the ceiling). This room is not one of the rooms in the reactor area, and is fairly close to the overseer's office. The controller is stashed inside of a locker, and can be obtained even should the quest not have been accepted prior to its collection.