A compact, lightweight and stylish electronic FLASH with built-in diffuser & LED Video Light - 4 x LR6, ZR6 or Ni-MH batteries(Not included) - Recycle time of 4sec (ZR6) - 200 flashes per set of batteries - Slave synchronization Compatible with Canon Digital EOS 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.