The Bower Autofocus Dedicated Illuminator Flash is a dedicated TTL flash for use with Nikon digital SLR cameras. The Illuminator features a guide number of 99' @ 100 ISO and a tilt head that operates from 0 degree to 90 degrees. A built-in slave mode provides a useful remote flash capability that can help eliminate shadows and over-saturated subjects. The flash covers an 18-55 mm range (in 35 mm/full frame format) and also offers red-eye reduction, automatic shutter speed setting and rear curtain synchronization for shooting at slower shutter speeds. The Illuminator is powered by 4x easily found AA batteries.