This mug was actually marketing swag from one of the law firms I work with. It is constructed with dual aluminum walls separated by a vaccum partition. It is the same tech used for Swell bottles. It keeps its contents hot (or cold) by minimizing heat transfer to or from the contents of the mug. The only complaint that I have is that it occasionally works a little too well. I mean this in the sense that sometimes I have to wait a little bit longer than I would like to for the coffee to cool down to a drinkable temperature, and it has resulted in a scalded tongue on more than one occasion.
The only downside (in my opinion) is that the mug cannot be used to warm up my hand. This isn’t always a desired characteristic. But on chilly mornings, it can certainly be nice to use a traditional mug full of hot coffee to keep my paws toasty. I have to credit Britt for bringing these. She packed the kitchen box. I probably would not have even thought to bring these. But I’m sure glad that she did!