You can either manual seal zipper part, or you can heat seal the open top section above the zipper, so that achieve storage effect, and these food storage bags can be applied many times Just open and seal, very easy to use for packing and storing, transparent window design allowing for a quick glance at contents inside. These resealable bags are made of polyethylene raw material, non-toxic and reliable material, you can put items in them safely Very suitable for packing coffee beans, bath salt, candy, pill, sugar, rice, cookie, tea, nuts, dried fruit, snacks, popcorn, beef jerky, or other food you want to store