The Stretto Humidifier is the perfect humidifier for your string instrument. This one is appropriate for viola or violin. It is critical to protect fine instruments from changes in humidity, be it when travelling, making the trip from home to the performance venue, or simply adapting to changes in the weather and season. The Stretto family of humidifiers is designed instrument to instrument to afford a perfect environment for yours. Stretto products offer ideal protection for any string instrument.