Sauna heaters have been developed in countries with long sauna traditions without necessarily paying much attention to design. In the search for a more contemporary and efficient design for sauna heaters Siim Nellis turned to the Estonian Academy of Arts in 2011. The product design students of the academy proposed different designs, among which one design stood out. It was inspired by a water drop and had a hemispheric shape. In 2012 the heater was developed for production and it became known as DROP. Unlike other sauna heaters before, DROP had a unique round shape, well-optimized use of metal and an increased stone capacity, which allowed the electric heater to produce a mild steam similar to wood-burning sauna stoves.
In 2015 DROP sauna heater won the prestigious Red Dot Award: Product Design, one of the most important international awards for exceptionally good design. DROP sauna heater was acknowledged for a well-implemented design solution.