The Olight Battery Magazine for the Olight M30 LED Flashlight keeps 3 x CR123A batteries from rattling in the battery tube and can also serve as a spare battery holder in the holster, attached to the lanyard or in your pack. 1 is included with the light. The Magazines also serves as a 'quick load' apparatus keeping your batteries together so the that user can keep sets of fresh cells together and even load them in the dark as the lanyard connector also serves as a polarity locator - no fumbling in the dark!