High performance Nitecore 18650 3.7V 2300mAH Li-ion rechargeable battery (1 per pack), with IC protection built-in. It is safe to use in your flashlight and cost effective. 

Features and Specifications:

• Purpose-designed for high-performance equipment. Safe, environment-friendly, high-performance 18650 cell.
• With built-in PTC to protect the battery from high current surges.
• Microporous barrier protects delicate internal components.
• Pressure relief valve activates in the event of a rapid temperature increase.
• Innovative anode design with high temperature resistance.
• High performance. A high output current of up to 4A makes NL183 compatible with various kinds of high-drain devices.
• Actual measured capacity is approximately 2300mAh which is 15% more than a common 18650 rechargeable cell.
• Positive end is a standard button size allowing maximum equipment compatibility. Compatible with most brands of 18650 flashlights.
• A NL183 battery can be recharged over 500 times, the equivalent of 500 pairs of CR123 batteries.
• Certified by RoHS,CE and UL
• Capacity: 2300mAh
• Voltage: 3.7V
• Electricity: 8.5Wh
• Charging Current: Maximum 2A. (1A Current recommended)
• Weight: 45.5g
• Diameter: 18.6mm
• Length: 70mm