There is a reason why this coffee mug is called the Radiator Mug, the bottom fins (called heat sinks) take inspiration from the radiator mechanics found within the PC or an engine, to keep things cool. Likewise these ceramic fins eliminate the need for a handle and keep your hands cool while holding a steaming cuppa coffee/tea.
Designer: Stephen Reed [ Buy it Here, Radiator Mug is available for $24 @ YD Store ]
Radiator Mug is available for $24 @ YD Store