This is a Canon Extender EF 1.4x III. It's priced lower than others due to some scratches. I occasionally used it with a "Roku-yon" (Canon EF 100-400mm f/4.5-5.6L IS USM) but haven't had much opportunity to use it, so I'm selling it. Although I haven't used it much, there are two scratches: one from a bump in the mountains and another that's not very noticeable. There are no issues with its functionality. It will be delivered in its dedicated case. Please only purchase if you understand that this is a used item.