This is a Proprietary Battery and ONLY works with our RC40 Rechargeable Flashlight. It will not work with any other flashlight.
It is designed with unique contact. The central part is positive and the ring surrounding it is negative. What that means is that the battery can be installed without the worry of positive and negative points being a particular direction for it is reversible. For your protection it is designed with over-charge, over-discharge, and over-heat safeguards. Charges in the light.