Simply detach the smaller inner tube and place this on the outside of the bag. Fold the excess wrapper over the top, and then sit the larger tube on top. Close the lid and voila. Watch as your food stays fresh for days. They work great on all sorts of things, open chip packets, open bags of dried goods, and can even help you store liquid in plastic bags. The sealer clip comes in 3 different sizes: small, medium and large.