Med Packs come in small, medium, and large sizes. Each container is filled with a cyan gel that can both heal and stabilize even the most grievous wounds inflicted on a person. A few Med Packs should always be kept in the Inventory in case of injury. Unlike ammunition, Med Packs take up one inventory slot each and are therefore "unstack-able." Pressing the "quick-heal" button automatically uses the smallest Med Pack in the player's inventory. It is revealed in Dead Space 3 that Med Pack technology has been available for at least 300 years as there are a great many of them amongst the S.C.A.F. installations on Tau Volantis and the fleet in orbit and the key ingredient is Somatic Gel.