The contract covers the purchase of between 300 and 400 man-portable air defence systems (MANPADS), including Chinese-made QW-12 and FN-16 missiles, the sources said. Iran needs to rearm after months of warThe sources spoke on condition of anonymity because of the sensitivity of the matter. The sources cautioned that, although the agreement had been signed, delivery schedules, quantities and other implementation details could still change. The QW-12 ​and FN-16 are shoulder-fired, infrared-guided surface-to-air missile systems designed to engage low-flying aircraft, helicopters and drones. Reuters previously reported that Iran was close to securing a separate agreement with China to acquire anti-ship cruise missiles, according to people familiar with those negotiations.