This is an unprotected, flat-top cell. Note that the other common brand weapon lights are not rated for un-protected cells such as this battery. Charge this battery with the UI2 Custom Label Charger or the D2 Custom Label Charger. SPECS Size: 18650 Approximate Diameter: 18.1mm Approximate Length: 64.9mm Manufacturer Rated Typical Capacity: 3000mAh Manufacturer Rated Wh Capacity: 10.8Wh Max Continuous Discharge Current: 15A Nominal Voltage: 3.6V Full Charge Voltage: 4.2V Weight: 48g TECHNICAL WARNING: Use caution as misusing or mishandling the battery may cause a FIRE or EXPLOSION which may result in personal injur Mfg: Cloud Defensive Llc