It can be found in Nellis Air Force Base, Pearl's barracks. It is located within the filing cabinet along with Col. Blackwell's key, which is used to unlock the box in the Vault 34 armory containing the pulse gun.
Due to current events, Staff Sergeant Daniels is hereby authorized to transport item no. T-11836A, codenamed "CIRCUITBREAKER," to the installation known as Vault 34 to be sealed in its armory for safekeeping until the manufacturer can retrieve the prototype for production.
Col. Roy Blackwell, USAF