I have a Food Saver. Bought it eight years ago.
A guy in Alaska taught me something about vacuum sealing…Let’s say you’re freezing fish. Put them in the bag, but don’t seal the top. Get 3-4 bags ready like that, fold up the tops, and close them with a paper binder clip. Put them in the freezer overnight. The next day, when they’re froze, put them in the sealer, suck out the air, and heat seal the top of the bag. By freezing the bag’s contents first, you don’t suck out juices. They can moisten the bag and keep the bag from sealing or holding it‘s seal over time.