These cylindrical lithium batteries are single use (non-rechargeable) and are commonly used in dog collars cameras flashlights medical equipment photo equipment electronic equipment and electronic games. The lithium battery technology provides you with the necessary energy for your camera ~ they offer quick flash recovery and can operate under extreme temperatures. Fits cameras such as many Nikon EM FE and FE2 and Leica M6 M6TTL M7 and MP models.