One battery per package. This is for the RC10, RC15, RC20, UC40UE, UC45, UC50 ONLY. It does NOT ship with any power cables. If you are ordering this for the UC40UE, you will need one of these cables: RC10/RC15/UC40UE Spare AC Charger or RC10/RC15/UC40UE Spare DC Charger. Will not work with any other flashlight. The FX-ARB-L1-2600 is a tailored 18650 rechargeable Li-ion battery (2600mAh) specifically for the RC10, RC15, RC20, UC40UE, UC45, and UC50 so you will never be without a power source. The unique contact design has the central part positive and the ring surrounding it negative. The design also includes over-discharge, over-charge, and over-heat protection.