The supreme electronic-flash of Canon"s Speedlite series, the Speedlite 580EX has a maximum guide number of 58/191 at ISO 100 in meters/feet (at 105mm focal length), faster recycling, more consistent color and enhanced controls are among the improvements that all photographers, especially those who shoot digital, will find useful. Ratio flash lighting of up to 8 - 1 when used with ST-E2 Transmitter & multiple 550 or 580EX"s Zoom, Bounce, and Swivel Head for best positioning Angle of Coverage 84-degrees (24mm in 35mm format) to 23.3-degrees (105mm); 114 (14mm) with included wideangle adapter Uses Four 1.5-Volt AA batteries - May use alkaline or rechargeable NIMH or Li-Ion Unit Size WHD - 3 x 5.3 x 4.5 / Weighs 13 ounces Includes Pouch, Hot Shoe stand Canon USA 1-Year Warranty