The Army of Taiwan uses the Antelope air defense system to back up the US-supplied Avenger. Both are mounted on Humvees, and both carry four infra-red fire-and-forget missiles. The Antelope, however, used a full-sized air-to-air missile (the Sky Sword 1) which gives it a range of 9,000m and a maximum engagement altitude of 3,000m. --Stephen V Cole