The Petrof P 135 K1 is ranked in to the highest, master built upright piano series. These are upright pianos with the greatest sound potential and that are therefore favourites of demanding professional pianists. They are suited not only to apartment interiors and music schools, but also piano recitals within an orchestra or in different public stages.

The instrument provides wider possibilities for a player to control the sound. The upright piano is handled by 3 foot pedals and a hand lever.