Some fighter aircraft specialized in combating other fighters, while interceptors were originally designed to counter bombers. Germany's most important air superiority fighters were the Messerschmitt Bf 109 and Focke-Wulf Fw 190, while the Supermarine Spitfire and Hawker Hurricane were the primary ones on the British side. Performance and range made the P-51 Mustang the outstanding escort fighter which permitted American bombers to operate over Germany during daylight hours.