Music Sorb is a synthetic silica gel product developed by chemical engineers in Japan to help moderate and control the relative humidity (%RH) inside a given area, such as inside your piano or musical instrument case. High humidity can cause wood to swell, challenging glued wood joints and breaking down wood fiber. Low humidity can pull moisture out of the wood cells causing glue joints to open up and prematurely cause the wood to become brittle. By balancing the humidity around your musical instrument, the devastating effects of wide humidity swings can be reduced. How does Music Sorb work? To begin with, Music Sorb is a silica based product, just like the typical moisture absorbing desiccants. But unlike a dedicated desiccant, Music Sorb has a special technology that allows stored moisture to be released when the %RH drops below a pre-determined range. An appropriate amount of Music Sorb in your musical instrument helps provide that humidity buffering or controlling effect. Music Sorb for pianos: · Cassettes (2.2 lbs or one kilogram) · Pouches (2.2 lbs or one kilogram) Music Sorb for stringed instruments: · Six 30 gram pouches in a re-sealable "six-pack" bag. One can store unused packs in the re-sealable bag for up to a year for future use. Music Sorb has a shelf life of up to three years as long as it remains sealed in its original packaging. Music Sorb should be replaced at least once a year to retain the effectiveness of the product. The manufacturer will stand behind the effectiveness of Music Sorb for one year from product opening. Click here to download brochure