Oxygen Rebreather: The oxygen rebreather is the oldest type of rebreather.
The advantage of using a gas different than pure oxygen is that it allows the diver to dive deeper than the 20-foot limitation of the oxygen rebreather. The gas is injected into the loop at a constant rate to replenish oxygen consumed from the loop by the diver.
Various industrial oxygen rebreathers (e.g., the Siebe Gorman Salvus and Siebe Gorman Proto) were descended from it.
Another important improvement, the V60 is submersible to 20 meters compared to the two meters of the X50, which means it can be carried without problems by Special Forces units using oxygen rebreathers
. The V60 can work in conjunction with Invisio in-ear protecting headsets and bone microphones, but the system is headset and microphone agnostic and can thus be used in conjunction with any other type of equipment.