The lower price of production compared to a column wheel model meant an average person could afford a chronograph for the first time. This would become one of the most popular chronograph movements ever made, with more than 3.5 million examples produced between 19. They refined this movement to become the two-pusher Cal. 47 had three pushers: One to start, another to stop, and a third to reset the counter. Just before World War II, Landeron developed the first cam actuated chronograph. Because they held the Breitling patents, Landeron was the exclusive supplier of column wheel chronograph movements until their expiration in the 1930's. Landeron's column wheel chronograph movements were famous, and the company supplied these movements to many militaries. FHF/Landeron became a founding member of Ebauches SA in 1926. In 1925, Landeron merged with Fabrique d'Horlogerie de Fontainemelon (FHF), being renamed Fontainemelon et succursale du Landeron. This movement production company took the name, Landeron. In 1924, Charles Hahn (son of the founder, who died in 1875), acquired the patents of Anatole Breitling and began producing chronograph movements. They produced watches at first, but moved into watch movement production in the 1920's. The company began in 1873, formed by Charles Alfred Hahn and his brother Aimé Auguste Hahn, and called Charles Hahn & Cie. Landeron was a Swiss watch movement maker in Le Landeron famous for chronograph movements.