The Caso zipper bags are very good quality and keep the vacuum. The Many Uses are awesome: This allows the food traveling last longer fresh, but also freeze anything or cook preserves vitamins in a water bath for. By zip fastener, the bag can be used repeatedly, which I like a lot more, each time to weld the vacuum bag. That is worth more if you want something long term freeze on a large scale.
However, since I am not convinced of the Caso-vacuum devices and Me for a rented apartment are way too loud, I use the Zebco vacuum pump that lets you manually can easily suck the air from these zip bags without noise, since the hand pump fits perfectly on the valve of this bag.