This is a Macro O Flash Ring for Canon 580EX 580EXII 5D 50D F170. This O-flash macro flash unit is a unique adapter for your hot-shoe flash unit designed to replicate the lighting effect produced by traditional, expensive, and heavy powered studio ring flash units.This is a Macro O Flash Ring of 100% brand new and high quality.The Macro O Flash Ring contains no electronics,no flash tubes and requires no cumbersome cables.The Macro flash ring is portable and lightweight,has been designed to take advantage of a camera's TTL metering capabilities.This Canon Flash Ring produced by traditional,expensive,and heavy powered studio ring flash units .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. The most best tools for macro photography.This Flash allows infrared AF assist beam pass through the flash ring .TTL functions will work normally when using this O-Flash.As with standard flash use,manual exposure control requires the use of a light meter or test-shots.