content: I had purchased this along with my 50mm f/1.8 mkII thinking that it would protect everything well and improve my photos. While it did do a good job protecting, everything thing else was horrible. First, with any picture I took that had a light source...that light source was reflected in green on the opposite side of my photo. Second, the filter got STUCK ON THE LENS. I had to have it professionally removed! If you don't mind the green reflection in your photos, then by all means purchase this. Otherwise...stay far away! It is not worth the $23.