Humidity regulator for musical instruments: Moisregart Violin Limited color: Pink - Maintains the humidity inside each instrument case at 40-60% for a long period (approximately 2 years from opening). - The sheet's raw materials are water-absorbing polymer and urethane resin. By using cutting-edge technology to reduce the particle size of the polymer to 0.5µ, the overall surface area of the particles is expanded, enhancing the moisture absorption and release effect. - Prevents cracking and warping of the instrument due to dryness inside the instrument case, and helps with the adjustment and maintenance of pegs and bow hair. Please refrain from purchasing if you are concerned, as this item has been handled by someone else.