Rebreather

The rebreather is a piece of headgear $$

Gameplay
The rebreather provides a Damage Resistance of 3, but no DT, and grants unlimited oxygen while submerged underwater. The player cannot drop or sell this item, and its condition will never degrade. It fills the mask slot, so it does not prohibit the wearing of headgear that only covers the top of the head (e.g., combat helmets). It cannot be worn with certain helmets, such as power armor helmets, or glasses (e.g. Dr. Mobius' glasses), but can be worn with most hats.

Location
The item is received from Jack at Nellis hangars during the Volare! quest if the player has a Science skill of at least 45, or a pressure cooker.

Bugs

 * The rebreather may sometimes be grayed out in the equipment list, thus appearing to be too damaged to be used without repair. This is purely a display bug and has no effect on its functionality.
 * After equipping the rebreather for the first time, if you unequip it any time before saving, your DT may not appear in the slot at the top of the screen under the Items menu in your Pip-Boy 3000, regardless of what else you are wearing. Only when you re-equip the rebreather does DT (and DR) reappear. This can be fixed by saving (confirmed on PS3) or rebooting the system (confirmed on Xbox) or unequip the rebreather when it says "DT" not "DR."