This is an adapter for the Rasbery camera v2 with a c-mount thread for microscope adapters or a replacement lens. The adpater is for the HDMI kit from (https://www.tindie.com/products/freto/pi-camera-hdmi-cable-extension/). The adapter have a thread (1/4-20 UNC) for a tripod. All the holes in the camera holder part is for M2 screws