This is an Angle Finder A for Canon film SLR cameras of the A series. It can be used with Canon's A series, but also with the T series. As the name suggests, you can change the viewing angle of the viewfinder, making it easy to set up compositions. There is dust inside the viewfinder. It's in a place that doesn't interfere with shooting, so I've been using it without any particular problems. I'm selling it to clear out my inventory. Please consider it. Thank you.