Love Your Instrument—for effortless humidity protection, use Boveda. Having been in the industry for more than 25 years, Boveda is a trusted and experienced brand in relative humidity control. But what does that even mean? Relative humidity (RH) refers to the percentage of humidity within an environment. In other words, it answers the question, 'HOW MOIST OR DRY IS THE AIR IN MY INSTRUMENT CASE?' Boveda's founders & scientists discovered that THE RIGHT RH HAS A HUGE IMPACT ON A WOOD INSTRUMENT'S PERFORMANCE & SOUND & SAFEGUARDING ITS CONSTRUCTION. Using Boveda, you'll maintain a precise moisture level between 45 and 55% RH—no more mustiness in your instrument case. Just slip the Boveda packs into the fabric holders included in this Large Starter Kit, position them in your case & forget about the packs. Refill after 3 months. USE THE BOVEDA LARGE STARTER KIT in an instrument case to maintain the right humidity for: a GUITAR, including acoustic, guitarrón, hollow-body, nylon string, semi-hollow body, electric or bass; LARGE STRING, including cello/violoncello, double bass/upright bass & hollow-body bass; & LARGE WOODWIND, including bass clarinet & bassoon. Subscribe & Save to get Boveda replacement packs sent to you automatically. Proudly Made in the U.S.A.