An unofficial, common fan-made fail-safe key replica, a large number of which were once sold on eBay

A number of keys are given particular importance in Lost by being shown on screen or specifically mentioned:

  • The key to the marshal's handcuffs. Kate unlocked one of the bracelets with the key she took from the unconscious marshal, who hit his head during turbulence, in episode "Pilot, Part 2". Kate then dropped the key in the plane when she reached for the oxygen masks. This key was lost in the crash.
  • The keys mentioned in Danielle Rousseau's distress message, heard in episode "Pilot, Part 2": "Brennan took the keys." It is unknown what those keys were.
  • The key to the marshal's safe deposit box number 815, which Kate used to open the safe deposit box in the New Mexico bank in episode "Whatever the Case May Be". How Kate obtained that key is still a mystery.

Anthony Cooper gave this safe deposit box key to Locke. ("Lockdown")

The key to Hurley's Camaro. ("Tricia Tanaka Is Dead")

The key to the DHARMA van brought to Hurley by Vincent. ("Tricia Tanaka Is Dead")