B
Bob Graham A nice heater available in three colors.
Advantages: heats up well or maintains temperature effectively. Simple to construct. Three temperature settings available / 55 degrees / 65 degrees / 75 degrees. Display. Aesthetic appearance. It even heats a ceramic cup - but the temperature of the drink is significantly lower.
Defects. There is no load switch, so if you forget to turn it off, it works all the time. No rubber coating, so it may slip.
Overall, very good design. I'll buy a glass with a flat bottom and the drink really stays warm. I recommend it.