Yellow reactor keycard
An electronic security key, color coded yellow. Used to open doors in Gecko's nuclear power plant.
This item can be found on the body of a dead Enclave soldier at the vertibird crash site in Klamath. It would seem that the player could use the keycard to open the respective yellow security level doors in the Gecko reactor, but it doesn't actually open anything. Instead, proper keycards can be found from around the plant and an electronic lock pick Mk II may also be used to open both the yellow and red doors.