Oxygen Filters

Oxygen Filters are portable consumable oxygen sources used from the backpack. When inserted into the backpack, they immediately begin producing Oxygen, first filling the backpack’s primary oxygen supply and then sequentially filling any connected Oxygen Tank. While at least one attached filter still has charge, the backpack’s oxygen supply does not decrease.

A single pack of Oxygen Filters contains four individual filters, and each one represents 20 seconds of operation for a minimum total of 80 seconds of air. In practice, they can provide more than that minimum if multiple tanks are available to fill during their run time, or if the player had less than a full Oxygen Tank when the filter was created. A fresh filter can fill the backpack tank and fully charge 7 more Oxygen Tanks, and begin filling an eighth before running out, when tested with completely empty tanks.

Oxygen Filters deactivate temporarily if they are connected to an Oxygen source, connected to another Oxygen source, or removed from the backpack. The blue ring on the filter turns on while it is supplying Oxygen and turns off when it is connected to another Oxygen source or otherwise not in active use. When disconnected from the backpack, the blue light remains in whatever state it was in at the moment of removal.

Because they begin working immediately, Oxygen Filters are useful as an emergency air supply for exploration and recovery. They are especially valuable when the player needs a fast refill without setting up infrastructure, or when moving between oxygen sources. Their behavior makes them more efficient than their minimum runtime suggests whenever there are additional tanks to charge.

• Oxygen Filters are best treated as a short-term backup rather than a permanent oxygen solution.
• A partially filled backpack or nearby empty Oxygen Tanks can increase the practical amount of Oxygen gained from a filter pack.
• The filters are spent sequentially, so the pack continues supplying Oxygen until all four filters are depleted.