I have a similar one from ebay, for my canon system. Mine either lights up 360 or 180 degrees. It's not a flash but basically just an LED lamp (like a petzl only round). Pretty bright, and was useful to have around last week during a power failure. It does help light up the subject when using a macro lens but I find it limiting in terms of it not being adjustable or positionable to try to reduce shadows. But, there are other options for that.

Dan