Red Pass Card (Offshore Rig)
From WikiRaider
Red Pass Card is an electronic key found in the level Offshore Rig in Tomb Raider II.
The Red Pass Card in this level is dropped by a guard in a long hallway. Obviously, you have to kill him to get it.
It slots into a Red Receptacle at the top of a barrel trap in the hallway to the left of the small corridor opened by the Yellow Pass Card.