Boveda B49HA-40-4P Humidity Control Refill - 4 Pack

Boveda 49% RH High-Absorbancy are specially designed for musicians who live in a climate with 50% humidity or more for most of the year. Not sure if this is you? Check your local humidity levels. (Lower humidity? Choose Boveda 49% RH for wood instruments.) Year-round extreme humidity? Formulated to protect wood instruments in year-round extreme humidity level of 50+% Protects instrument from warping and mildew build-up while balancing the humidity level in your case. Keeps wood instrument in the safe zone—Automatically achieves and maintains a constant relative humidity (RH) level between 45% and 55%. Prevents humidity fluctuations. Exposing your wood instrument to humidity swings day after day—going in and out of air-conditioned venues or traveling by air—can throw off its measured alignment and cause permanent damage. Tested in a lab at rainforest-like conditions! Absorbs 3x more moisture than Boveda 49% RH. Unopened, Boveda can stay fresh for up to 2 years in its overwrap and sealed bags.