I actually bought this at Teavanna as a Christmas gift for my husband-buy it here because at Teavanna they are an extra $10.My husband is a Police Officer who works nights. He was always getting frustrated with regular travel mugs as they didn't keep hot long enough on cold nights. And the plug in style of thermos doesn't work because there aren't any available adapters in his police car. He prefers to drink tea so when I saw this I knew we should try it. He says this is the perfect thing for cold winter nights when he's stuck in the car for hours and can't go anywhere!