Sliding the thumb rest into the accessory shoe enhances the ergonomics of the Leica M10. With the thumb pressed up against the thumb rest, the camera can be held much more steadily and is easier to handle. It makes single-handed shooting much steadier and enables the use of longer shutter speeds without the risk of camera shake. The thumb rest is CNC-machined from aluminium, has the same Eloxal finish as the Leica CL and, when attached, merges with the camera in visual unity.