SUS304 and leather with insulation inside. A small idea solved the contradictory phenomenon of reaching the target temperature quickly but keeping it constant. Due to the low specific heat of the metal, the target temperature is reached quickly, but the temperature is preserved by external insulation.
It is based on capillarity. Thirty two interior ridges (get thicker as it goes down) pull the water through the brewer faster than gravity alone could.
Precise nozzle and a slope of 31 degrees enable an ideal flow from brewer to cup. Too restrictive a flow, and the coffee would be over-extract and muddled. Too open, and the coffee would be under-extract and unpredictable.