Product Information: Boveda Welcome to Boveda maintenance free 2-way humidity control for fretted, bowed and wood woodwind instruments, including: acoustic guitars and basses; guitarróns; violoncellos; double basses; bass clarinets; bassoons; and large cases. Boveda creates the perfect humidity balance for your wood instrumentwhatever its surroundings call for. Make any case more protective with Boveda. Product Features: Takes the work out of managing humidity for wooden instrumentsfretted, bowed or woodwinds. Automatically humidifies and dehumidifieswhatever your instruments surroundings call for. No more foams, hoses and sponges that require constant attention and could damage an instrument, affect the sound and playability and lead to costly repairs. Achieves and maintains a constant relative humidity (RH) range of 45% to 55%the safe zone for wood instruments. Uses only pure water and all-natural salts sealed inside a leakproof membrane. Remove Boveda's plastic wrapper. (Do not open the Boveda itself.) Just slip unwrapped Boveda into the pouch(es) of its leak-resistant fabric holder(s). (A Boveda protective holder is soft, like a polishing cloth.) Place in case and close the lid. Always keep your case closed when using Boveda. Body type: Solid Body For more information and specifications, please refer to the manufacturers website