The third prototype Mosquito served as the prototype of the warplanes fighter variants, and the first production fighter variant was the NFII which incorporated a solid nose containing four 20mm Hispano cannon, four 0.303' machine guns and AI MKIV airborne interception radar. The most numerous variant of the Mosquito was the FBVI which took part in some of the most celebrated precision raids of the entire second world war. The Mosquito FBVI was optimised for low level operations and carried the devastaing armament of the fighter with the ability to carry a substantial bombload in an internal bomb bay as well as bombs, or rockets under the wings. The Mosquito FBVI was used in large numbers as a day and night fighter, night intruder, fighter bomber and light bomber.