The Messerschmitt Bf 109K “Kurfürst” is a German fighter aircraft and the last of the Bf 109 family put into mass production during World War II. Its main differentiating characteristics were a streamlined airframe, new canopy and the installation of a Daimler-Benz DB 605 "DC" model engine, the most advanced of its kind, equipped with a water-methanol injection system. While a number of experimental and specialised models existed, the Messerschmitt Bf 109K-4 was the only truly mass-produced variant. It was the fastest Bf 109 model reaching over 700 km/h at an altitude of 7,500m. The interior motorkanone was replaced with an MK 108 autocannon, capable of bringing down any aerial or unarmoured target in a single hit. Less fighters of the Kurfürst model were created than its predecessors due to the appereance of jet fighters such as the Messerschmitt Me 262, which would begin displacing propeller fighters within the Luftwaffe from 1945 onwards.