The viola dampit is a "must have" tool that helps keep your viola from cracking. The inner part of the dampit has a sponge that absorbs water disperses humidity throughout your instrument. Cracks and open seams can be difficult and expensive to repair, but they are easily prevented by regularly refilling and keeping your dampit inside your instrument. It is highly recommended to use a dampit in especially dry conditions.The original humidifier for string instruments, Dampit has been protecting wood instruments for over 40 years. The Dampit is the most economical, efficient and time-tested system for keeping your instrument properly humidified.