Battery orientation:
For Laser Cartridges with two o-rings: the positive side of the battery should be facing the side of the laser cartridge where the laser comes out of.
For Laser Cartridges with three o-rings: the positive side of the battery should be facing the side of the laser cartridge that contains the laser activator button "primer."
A small plastic tab is inserted in the battery stack inside the laser cartridge to prevent battery discharge during storage or shipment. This tab should be removed from the laser cartridge prior to use.