The SB-910 is Nikon's most sophisticated and powerful Creative Lighting System portable Speedlight designed for use on camera as well as for complete wireless control in the studio or on location.
Features:
Flash Modes: i-TTL, TTL-AUTO, Manual
Guide Number: 34 m/111.5 ft at ISO 100 (35 mm Zoom-head Setting), 48 m/157.5 ft at ISO 200 (35 mm Zoom-head Setting)
Interfaces/Ports: Hot Shoe
Batteries: 4 x AA Nickel Metal Hydride (NiMH) Supported, 4 x AA Alkaline Manganese Supported, 4 x AA Lithium Supported