Oz Kits allow humans to breathe on the airless surface of Elpis. It is a small device that is typically worn on the shoulder, and when it detects a drop in air pressure, it erects a small air-retaining forcefield bubble around the head of its wearer, thereby providing a portable supply of oxygen. Depending on the Oz Kit's O2 capacity, the air supply typically lasts between fifty seconds to three minutes. Once the air supply is depleted the bubble cannot retain itself, vanishing and leaving the wearer to slowly asphyxiate until more oxygen is found.