Neewer TT520 Flash Speedlite for Canon Nikon Sony Panasonic Olympus Fujifilm Pentax Sigma Minolta Leica and Other SLR Digital SLR Film SLR Cameras and Digital Cameras with single-contact Hot Shoe Compatible with Canon Digital EOS and Nikon DSLR cameras This flash has a guide number of 33 (ISO 100), a color temperature of 5600K+200K, and 4 AA batteries (Alkaline or Ni-MH are usable) power the unit. One flash may last 1/800s~1/2000s depending on the 1/8 - stop increment selected. One one set of batteries, expect 100-1500 flashes (AA alkaline batteries used) and a recycle time of approx. 0.5-5s (AA alkaline batteries used). The TT520 vertically rotates 0~90 degrees, and it horizontally rotates 0~270 degrees.