The Canon Macro Ring Lite MR-14EX is for macro shooting and is loaded with features and capabilities. With Canon's E-TTL, it takes full advantage of the flash performance of the EOS-1V, EOS-3, and other E-TTL supported cameras. Twin circular flash tubes fire at even power, or can be varied over a six-stop range. One or more 580EX, 550EX, 430EX, or 420EX Speedlites can be used as wireless slaves along with the MR-14EX. The controller unit has an illuminated, informative LCD panel. Accepts optional hi-capacity battery packs.