1. With an inner valve to keep it fresh, this is a zipper bag for coffee that is suitable for roasted beans.Besides coffee, you can also store beans, candy, sugar, rice, baking, cookies, tea, nuts, dried fruits, dried flowers, powder, snacks, grains and more. 2. Inner valve (check valve) function cuts out the outside air and releases the carbon dioxide gas inside.Preservation is fresher, tastier, and lasts longer.