GHD-01 is a humidifier specially designed for guitar, humidifying your guitar precisely and preventing it from shrinking or cracking. Most of the guitar humidifiers on the market now are placed between guitar strings, so the neck is taking an additional tension during the period of humidifying. To solve this problem, designed GHD-01, an ingenious way to place a humidifier on the guitar without spreading the strings. Moreover, GHD-01 has an indicating , indicating the humidity for guitar in real time.