The Speedlite EL-100 from Canon is a sleek strobe designed to give you more control, flexibility, and power than your camera's built-in flash. Offering a guide number of 85.3' at ISO 100 and 50mm, this flash also has a 90° tilting range, 330° rotating, and a similar spread to that of a 24mm to suit working in a variety of indoor and outdoor situations. The mode dial on the rear allows for easy group selection or it can also be set to AUTO to allow your camera to determine when a flash is necessary. Also, for off-camera use, an optical receiver allows for triggering from up to 36' away. Adjustable output settings from 1/1 to 1/128 power. The stroboscopic setting for rapid, repeating firing can be used for creative effects during long exposures. Accepts two AA batteries as its power source.