MOISS2-GC1 is the acoustic guitar humidity controller to absorb and release moisture. It is able to fit in 100mm diameter soundhole. MOISS2-GC1 humidity controller is the first of its kind to both absorb and release moisture, depending on the humidity level, which is displayed to the user. Manufactured in Japan, MOISS2-GC1 is designed to absorb twice as much moisture as silica and does so in five-times the speed. It keeps relative humidity at 50%.