Oasis OH-3P Plus+ Humidifier Combo OH-5 & OH-2OH 5: While the original Blue Oasis provides sufficient humidity in many environments, it is not effective everywhere. The humidity demands of the desert, mountain states or frigid north exceed the humidification capacity of the OH 1. For this reason, we have developed the OH 5 Plus+ humidifier. The OH 5 Plus+ is the same size and shape as the original blue Oasis, but is has a different liner which provides 50% more humidity output. Because the OH 5