I have received the Ozeri Instavac Food Storage Set 8 piece set (4 Containers with Lids) . I tried these bowls out and I really like them a lot, for storing and keep my food fresh. I tested these out and they actually do keep the food fresher for a longer period of time, which makes the food taste great even longer and keeps me from having to throw my food out and helps me to keep my money in my pocket. It also has a dial that I can set the date to so i know when my food was purchased.To use the Ozeri Instavac Food Storage set,all you have to do is to fill it with the food you want to keep fresh and lock down the snap and seal lids, and then set the dial with the date you purchased it and then pushed down on the lid and the Instavac will go to work and get rid of the air so your food will stay fresher longer,the storage set has a wave pattern on the bottom of the bowls to help keep water and moisture away from your food,.The Snap and Seal locks on each side and I can open them with one hand and they are also BPA free and also Dishwasher Safe and Microwave safe and Freezer safe. The 4 containers comes with Lids and their sizes are 21 cups (5.0 liters) 12.7 cups (3.0) 6.3 Cups(1.5 Liters) 3 cups (0.7 Liters). These has a built in Instant Vaccum in each four bowls, with a date dial on each of them as well. They all store inside of each other which is a great storage saver.I recommend this product, especially if you want your food to be kept fresher. I received this product for free for my unbiased opinion and my opinion is solely my own.