Our shallow case humidifier is a modified version of our OH-6 case humidifier. It is shorter than the OH-6, so it can stand upright in a shallow case. It comes with a different clip than the OH-6. 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. The also OH-26 holds about 1/3rd less water than the OH-6 and only takes two syringes to fill it the first time. The OH-26 will only fit cases where there is an open area for the humidifier to fit. OH-26 was designed specially to fit mandolin cases, but is also suitable for other small instrument cases.