2.4 GHz Wireless Radio TTL System Compatible with Olympus TTL Guide Number: 137.8' at ISO 100 and 75mm Zoom Range: 12-75mm LED Video Light Tilts Upward to 90° Rotates Left & Right 180° Recycle Time: 1.5-2.5 Seconds IPX1-Rated Weather-Sealed Design Runs on 4 AA Batteries