Polaroid O Ring Flash Adapter For The (Canon 580EX, 580EXII & T2i, T1i, XSi, XS, XTi, XT, REBEL) + (Nikon SB800 & D300, D200, D100, D70) + (Nikon SB600 & D1, D2, D3, D700) This O flash Is A Unique Adapter For Your Flash Unit Designed To Replicate The Lighting Effect Produced By Traditional, Expansive, And Heavy Powered Studio Ring Flash Units TTL Functions Will Operate Normally The Best Flash For Macro Photography it is portable and lightweight, has been designed to take advantage of a camera's TTL metering capabilities. Because this flash relies on the hot-shoe flash to generate its light, it contains no electronics, no flash tubes and requires no cumbersome cables. The light distribution is accomplished through a sophisticated system of internal prisms, reflectors and light-shapers designed to distribute and project the light evenly around the lens. This Flash allows infrared AF assist beam pass through the flash ring.