The Opteka EF-790 DG SUPER i-TTL is designed to work with the all Nikon digital SLR cameras, It has a maximum guide number of 148 feet or 45 meter at 85mm focal length (ISO 100).The projection angle of the flashgun is set automatically to match the len"s focal length ranging from 24mm wide angle to 85mm medium telephoto. It also incorporates a built-in reflecting plate and diffuser that can be slid out from the top of the flash head for soft lighting effects. The bounce flash head can be tilted 90Deg upwards and can be swiveled 180Deg to the left and 90Deg to the right. In addition, the flash can also be set manually at 6 different power output levels or can be utilized as a wireless slave. Features ~ Bounce& swivel head - Flash can be tilted 90Deg upwards and also can be swiveled 180Deg to the left and 90Deg to the right ~ AF assist - Autofocus auxiliary lamp helps the camera to focus in low-light ~ Illuminated LCD panel ~ Built in Reflecting Plate and Diffuser ~ Front and Rear Curtain Synchronization ~ Battery-saving mode shuts down power after 5 minutes ~ 1 Year Warranty Specifications Type: Shoe Mount Guide No:148" (45 m) at 85mm AF Illuminator:3.3ft-20ft/1-6m (50mm Lens) Flash Duration:1/1000 to 1/20,000 second i-TTL Dedication:Yes Bounce Head:Yes Swivel Head:Yes Recycle Time:0.5-9 seconds (based on fresh batteries & full power) Power Source: Four rechargeable "AA" batteries (Lithium, Ni-cd & Ni-MH) Dimensions:72mm x 100mm x 125mm Weight:270g (without batteries )