FN-6 (FN = FeiNu, 飞弩, meaning Flying Crossbow), is a third generation passive infrared (IR) man portable air defence system (MANPADS). It was developed by China, and is their most advanced surface-to-air missile offered in the international market. Specially designed to engage low flying targets, it has a range of 6 km and a maximum altitude of 3.5 km. The FN-6 is in service with the People's Liberation Army (PLA), and has also been exported to Malaysia, Cambodia, Sudan and Peru. Based on FN-6, China has developed a number of other MANPADS, such as HN and FY series, as well as other vehicle-based short-range air defense systems such as FN and FB series.