This item is definitely a work-in-progress! This is an adapter which fits a Nikon lens on one end and a piece of ground glass on the other. The idea is that the lens projects the image that it see's onto the ground surface of the glass, making it easy to see. It creates a cool optical effect and is a stepping stone towards doing some other cool imaging projects. Here's a video of what it does! The lens side of the tube will fit a Nikon F-Mount compatible lens. This version is a little tight, but you shouldn't have much trouble attaching the lens. The lens in the photos and in the video is a Lens Baby tilt-shift lens for a Nikon body. The ground-glass side fits a 50mm ground glass available from Edmund Optics. In the video I am using a 220 grit glass.Printing is very easy, just print with the lens-side down. The lens side has three locking blades. I printed my first version out of ABS with 10% infill.