A Ledlenser lithium-ion rechargeable battery in AAA size, 3.7 V and 320 mAh, listed as the replacement cell for the Ledlenser M3R torch. Although it is the same physical size as an AAA battery, it runs at lithium-ion voltage, so only use it in lights designed for it and never in a device made for standard 1.5 V AAA batteries. We could not find the maker's own listing for this spare part, so confirm it matches the battery in your torch before ordering.