More than 770 exhibitors from 76 countries are at the defense show in Riyadh, which opened Sunday and runs until Thursday. China has a large presence, displaying a full-scale model of the Wing Loong-X unmanned aerial vehicle. This drone is described as the world's first uncrewed aircraft made for anti-submarine warfare. It first appeared overseas at the Dubai Airshow in November. Military analyst Fu Qianshao told CCTV, "It was developed and modified for the export market" and has a long endurance of about 40 hours with a maximum range near 10,000km (6,200 miles). This gives it an edge over manned anti-submarine aircraft like the US Navy Boeing P-8, which flies for only 10 hours. China also shows a model of the CH-9 drone, from the latest Caihong (Rainbow) series, known for medium-to-high altitude and long endurance. The CH-4 drone has already been sold to Middle Eastern countries, including Saudi Arabia. A China Aerospace Science and Technology Corporation representative said the CH-9 has nine mounting points and can carry up to one tonne of payload, suitable to strike important targets. More than half of Middle Eastern arms imports come from the US, but Chinese military drones, such as the Wing Loong and CH series, are growing in demand there. Norinco displays a 10-tonne sea drone with a vertical launch system for maritime strikes against smugglers and illegal vessels. Other exhibits include the Golden Eagle MR150B UAV and the FL-300C suicide drone, also known as loitering munitions, which are changing modern warfare.