- Allow to use Leica M39 threaded lenses on Leica M camera - Focusing and aperture must be set manually - Preserve all focusing range up to the infinity point - Ring mount made of copper alloy - For lens version: 28mm / 90mm Compatible: - Lens: Leica M39 screw mount lenses: (28mm and 90mm focal length) - camera: All Leica M LM mount cameras: M9 M8 M7 M6 M5 M4 M3 MP Package - 1 x Lens Adapter