Instruct: Classify a review into positive or negative sentiment.
Query: Just useless

I use Vacu Vin stoppers for my wine and have been very happy with them. But this...it only holds a seal about one out of every four times I try. And how do you know when it's held? By breaking the seal. It's just a crapshoot as to whether the food is in a vacuum or not. So I just don't use it.