Color Grayish White Model 18650P-3.7-3100G Quantity 1 Piece Material Li-ion Cell Type Lithium Ion Battery Model 18650 Head Type Button Top Mark Capacity 3100 mAh Actual Capacity 3100 mAh Voltage 3.7 V Rechargeable Yes Rechargeable Times Others1000 Built-in Protected Circuit Yes Over Voltage Protection Yes Short-Circuit Protection Yes Over-Charging Protection Yes Over-Discharging Protection Yes Mercury Free Yes Other Features - Cell: Soshine 18650 3100mAh; - 3.7V 18650 battery; - Discharging and charging protection circuitry built-in - Protective circuitry kicks in when voltage is over 4.2V while charging 2.75V while discharging; - Emergency current cut off by PCB 8.0A. Packing List 4 x 18650 3100mAh batteries with protection 1 x Battery Case