Yes, they definately work! I used to sell Tupperware for a while and was hesitant myself when they first came out. So, I tried it and it is amazing. Not to sound gross, but I've had a head of lettuce last over a month in the large round fridgesmart. Just read the side label to know about the vents being opened or closed. Oh, grapes last forever as well. I mean they are nice and crunchy like when you buy them in the store!