The Oasis OH-26 Mandolin Humidifier helps prevent mandolin body cracks due to dry conditions.
The mandolin humidifier from Oasis is a modified version of their OH-6 case humidifier. It is shorter than the OH-6, so it can stand upright in a mandolin case.
The clip is shorter to fit the reduced depth of the mandolin case. The clip also has a wider top so it can span the side of a plush case.
The humidity output is reduced from that of the OH-6 because the area to be humidified is smaller.
Please note: The OH-26 will only fit cases where there is an open area for the humidifier to fit (F style).