Keep your instrument properly hydrated with the Boveda 2-Way Humidity Control Kit. It will keep a perfect balance between 45-55 relative humidity regardless of where you travel or the weather. If you live in an extremely dry area, or you run your heat during the cold, winter months, these Bovedas are invaluable. Also, if you live along a very moist coast, this will help keep your instrument from getting water logged.
How to Use: The Boveda inserts go into a soft pouch, which you keep inside your case. The case becomes humidity controlled. Take your instrument out of the case for practice, keeping the case closed. Put the instrument back into the case after practice, close the case. The inserts need to be replaced every 3-6 months, depending on how hard they have to work. Keeping your case CLOSED is the key, whether your cello is in it or not. Also works for violins, violas and basses.
The large kit comes with 4 inserts and 2 soft, fleece pouches.
The small kit comes with 2 inserts and 1 soft, fleece pouch.
If you just need the insert refills, they come in packs of 4, and you can find them here.