Tarcus 8.5mm f/2.8 pinhole probe c-mount lens Little probe lens that allows you to photograph very small things around corners, similar to periscope set-up used in filming miniatures for animation or special effects in film production. No focus ring, move the camera or the subject. Glass is in good condition. Aperture ring quite firm. Only for macro. What you see is what you get. Any questions please ask I used this on my BMPCC OG with an MFT adaptor. It’s not full frame, but gives a cool effect.