Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Excellent thermos

I bought this thermos so I would have something that would keep my tea hot while I drank it at work. This thing is amazing. I had made my tea and put it in the container (priming it with hot water first for about 15 seconds before putting the tea in) and brought it to work. I was so busy at work that I forgot about it and towards the end of my day, I pulled it out expecting maybe lukewarm tea, but it was still steaming hot about 20 hours later. Excellent product!