Card Key

The Card Key is a device that helps Snake to get to several places in Metal Gear Solid The Darpa Chief gave him lEvel 1 and Kenneth Baker gave Him Level 2 He got aaa level 3 card from a Guard level 4 from Dr Emmerich aswelll as level 6 later on and level 5 from Merly and Level 7 from Vulcan Raven.