Our ED-SEF220A External Flash is designed to work on the hot shoe mount of the Samsung NX series cameras. The flash is compact, lightweight and provides automatic TTL exposure control. For its compact size this is a very powerful flash with a Guide Number of 16' (4.9m) in the Wide Mode and 22' (6.7m) in the Tele Mode, but the A-TTL allows for subtle low light flash and fill-flash photography.