The instruments are characterized by our innovative design concept, which we invented in 2000, and which has been continuously further developed and patented. The concept is based on the idea of transferring all the outstanding features of our largest concert grand piano, where possible, identically to the smaller instruments. For example, from tone 44 to 88, the large scale (string design) of a concert grand is used in models of different sizes. The design of the soundboard is also identical to that of the largest concert grand. As a result, we achieve the same sound characteristics in all grand and upright pianos of the Konzert series as in our large concert grand K 280. In addition, the design of the large K 280 action has been transferred identically in the smaller grand pianos. The vertical piano actions have been optimized in accordance with the grand piano actions in order to enable the pianist to achieve almost the same speed of repetition as with a grand piano.