The Leicavit M fast winder is mounted in place of the base cover, and allows experienced photographers to shoot up to two frames per second without taking the camera from their eye - independent of batteries. Just unfold the lever, pull it back to its limit, let it whip back and take the picture. The Leicavit-M fits the Leica MP, M7, M6TTL, M6, M4-P and M4-2.