Don't be fooled, it's not really a bluetooth speaker. Its unusual appearance is due to its rounded edges. It fits perfectly in your hand, and you can enjoy your coffee whenever you wish. Perfectly designed down to the last detail The Fellow Carter Thermo Mug is not only beautiful to look at, but also has a few special touches. The first thing worth mentioning is that its double stainless steel walls are coated with a ceramic layer. This ensures that the coffee inside retains its true flavour and aroma for up to 12 hours (for hot drinks) and 24 hours (for cold drinks). Another advantage is the leak-proof seal, so not a drop of your coffee or tea goes to waste. Direct coffee extraction Fellow Carter has one more super feature, though. It was also designed for all coffee lovers who master alternative coffee brewing. It's compatible with most drippers and even the Aeropress manual coffee maker .