The Fujifilm EF-X20 is an external shoe-mount TTL flash unit designed specifically for the Fujifilm X-Pro1 compact system camera. It is a compact fixed-head flash that has a guide number of 20 (GN20) and incorporates an output control atop the unit that adjusts manual power output in 6 steps from full power to 1/32 or TTL flash compensation in 1/3 stop increments.