Only Adjustable Humidifier for Musical Instruments (Purple) By HUMISTAT USA Prevents cracking, warping, shrinking, sticking keys and pads Enhances tone and slows aging Only adjustable humidifier - refillable, reusable, low maintenance For Violins, Violas, Mandolins, Ukuleles, Piccolos, Fifes, Flutes, Clarinets, Oboes, English Horns, Recorders, Pennywhistle and more comparable instruments