Designed as a lightweight, maneuverable fighter, the P-65A4B, nicknamed "Bitty Baby" at an unknown time for unknown reasons, served its intended role excellently and replaced the Tri-Wing's role as the main fighter. The Tri-Wing was still in service but only as an interceptor. Its armament consists of three guns that vary in caliber, but are most often 12.7mm machine guns with 7.62mm machine guns or 20mm cannons instead on some models, depending on the pilot's preference. It outclassed the P-65A4A in every regard, though that had already been replaced by the Tri-Wing which this one is replacing. Though it is extensively used by the US military, it has also found extremely heavy use in coastal and station defense roles.