Unicorn Helmet Mount. The Unicorn Helmet Mount is suitable for action sports like bike riding and skiing. It is not suitable for skydiving, bungee jumping, wing-mounted flying and other high-speed aerial sports scenes where the mount can get caught in a parachute. Compatibility: X3, ONE RS (1-Inch 360 excluded), ONE X2, GO 2 (GO 2 must be assembled with the Carbon Fiber Extension, sold separately), ONE R, ONE X