I purchased to Canon 580EX flash units. I expected to learn how to use one as a secondary flash from different angles. However, I found that by using a Gary Fong Light Sphere, I rarely every had need to do this, so it has pretty much sat in the box. I do not think that I have used it even once. Hmm, I might have used it for about twenty photos just to test it; not certain. The UPC is missing from the box. Everything else is essentially new in box.