Revodream P is a PO2 monitoring electronic with a Head Up Display (HUD). Reliable, and easy to use, it can be connected to one or two cells. The HUD has three LEDs (orange, green and red) to indicate the PPO2 value. When you have the correct PPO2 (Partial Pressure of Oxygen), the HUD flashes continuous green: green means “OK, safe.” Small deviations over or under will result in a pulse of orange (low PO2) or red (high PO2), together with the constant green LED. When deviation is dangerous, the green will disappear and only red or orange pulses will remain.