Silver Key (Sinking Submarine)
The Silver Key is a key found in the level Sinking Submarine in Tomb Raider Chronicles. Admiral Yarofev gives the key to Lara after he tells her about the escape pod and its need for an air supply.
The Silver Key is used to unlock a door leading to a room where Lara finds the Oxygen Canister for the escape pod.
In the Russia section there are also other Silver Keys: two keys are found in The Base, and one key is found in The Submarine.