ZojirushiSM-TAE48SASZ Stainless Vacuum Mug, 16 oz, Ume Silver

Immediately I loved it when I received it! However on my first time using it, I put carbonated water in it, and it leaked. I suppose the bubbles and pressure caused the seal to be broken.

Awesome cup. I can have a hot cup of tea on my desk while working for at least 8 hous. Also, this is the only cup I trust to put in my shoulder bag.

I use the bottle for hot coffee. The bottle keeps the coffee hot for over 6 hours. It really works!! I purchased one for my son, he uses the bottle for cold beverages, he says it keeps liquids cold for close to 24 hours.

Not sure how real the negative reviews are - I have 6 different zojirushi mugs/thermoses with the locking mechanism and I don't have an issue with either one of them and I have had them for over a year and use them daily. Plus the locking isn't really necessary as nothing leaks if the lead is closed.Excellent design, drinks stay hot or cold for hours and hours. In the Florida summer heat, this mug in a super hot car will keep the drink ice cold. I wouldn't use any other brand.