all air can be squeezed out. With double zippers, there won't be leakage, so the food can be kept fresh for a longer time. Also, the zippers can be zipped up and unzipped for many times. EASY TO OPERATE: Comes with a hand pump, it is convenient to vacuum. The air valve on the bags are with self-sealing design. So you just need to align the pump to the air valve and start vacuuming. After vacuuming, you don't need to put a lid or sticker on the air valve. THREE SIZES: The vaccum food storage bags kit includes 10 bags with a size of 22x21cm, 10 bags of 26x28cm, 10 bags of 26x34cm. You can keep food separately by putting them in different bags so that there won't be odor taint. There are also 4 cooking clips and 4 sealing clips in this kit, which makes food storage more convenient. WIDELY USE: The vacuum food storage bags can be used to store all kinds of food, such as vegetables, fruit, meat, beans and so on. When food is stored in these bags, it can stay fresh and clean for a longer time. There is label on the bags for you to write down date and other information about the food. It is very helpful to know how fresh the food is. Specifications: Color: Transparent Item Type: Vacuum Food Storage Bag Material: PA PE Bag Size: 22 * 21cm / 8.7 * 8.3in 26 * 28cm / 10.2 * 11.0in 26 * 34cm / 10.2 * 13.4in Gross Weight: 650g / 1.43lbs Notes: 1. Size information is just for reference only, please allow 1-2cm (0.4-0.8 34;) differences due to manual measurement, thanks. 2. Item color displayed in photos may be showing slightly different on your monitor since monitors are not calibrated the same. Package List: 10 * Bags (Size: 22 * 21cm) 10 * Bags (Size: 26 * 28cm) 10 * Bags (Size: 26 * 34cm) 1 * Hand Pump 4 * Cooking Clips 4 * Sealing Clips