Thread Adapter. Practical and versatile. The thread adapter is supplied with a special tool for mounting it on the camera. Once mounted, any Leica correction lens can be used on the M10. Particularly practical: the thread adapter can also be used for mounting the Leica anglefinder M and viewfinder magnifiers on the M10. The thread adapter and mounting tools are supplied in a Leica SD card case for safekeeping when not in use.