This is an adapter for m12 (s-mount) lenses. It can snap on your existing board-mount lens holder and is useful if you want to use lenses with longer focal length. The tube widths can be adjusted to the lens holder and should snap on tightly. You might want to drill a hole for those M2 screws for better mechanical stability if in a shaky environment. It has originally been designed for ELP USB cameras that can be found on Alibaba, Amazon,... I uploaded a few more notes on my pages: http://voxel.at/voxel/blog/macro-photography-m12-usb-camera-modules This is an adapter for m12 (s-mount) lenses. It can snap on your existing board-mount lens holder and is useful if you want to use lenses with longer focal length. The tube widths can be adjusted to the lens holder and should snap on tightly. You might want to drill a hole for those M2 screws for better mechanical stability if in a shaky environment. It has originally been designed for ELP USB cameras that can be found on Alibaba, Amazon,... I uploaded a few more notes on my pages: http://voxel.at/voxel/blog/macro-photography-m12-usb-camera-modules Update: I cut the m12 thread as well which should improve printing and added reinforcement blobs for stability and looksSimply print with 100% infill, preferably in black to avoid light sneaking in. Depending on your printer, you might need to play a little with dimensions to get a tight fit.