The ZipLock system is totally manual, so you can do it anywhere without batteries, and you can re-seal the bags.

I was surprised how well they worked. I also wash and reuse them, and they still hold their seal (which I did wonder about), but I did wash them by hand with hot tap water, not a dishwasher. The only thing I don't care for is the scored design of the plastic bag itself (inside and out) which may trap food particles. And I would never reuse them after raw meat.

Sue