Canon MR-14EX Macro Ring Lite for Canon Digital SLR Cameras
Canon's Macro Ring Lite MR-14EX for close-up and macro shooting comes  equipped with many features and capabilities. Utilizing E-TTL (enhanced through- the-lens mode) technology, it takes full advantage of the flash performance of  the Canon EOS-1V, EOS-3, and other E-TTL cameras, and also supports E-TTL  wireless auto flash, when used with at least one Canon 550EX Speedlite flash.  The circular twin flash tubes of the MR-14EX can fire at even power, or vary  between themselves over a six-stop range. The controller unit has an illuminated  LCD panel, and the MR14-EX also accepts optional high-capacity battery packs.The MR-14EX attaches directly to Canon's EF 50mm f/2.5 compact macro, EF 100mm  f/2.8 macro (both versions), and MP-E 65mm macrophoto lenses, and can also be  used with EF 180mm f/3.5L macro USM via the Macrolite adapter 72C.