At some point you'll want to replace the inner pouch of your Fresh Helment Sack. You can expect the product to endure anywhere from 3 to 6 months depending on the temperature and the humidity level and of course how much you sweat. You will probably want to replace your the inner pouch more often in the hot, humid summer months. Remember you can extend the life of your product by regenerating the inner pouch in the microwave. See the instructions for details.