Intsun 2pcs 3.7V 18650 4000mah Rechargeable Li-ion Battery with PCB and 18650 battery Charger for LED Flashlight, Headlamps, search light lamp, etc No memory effect, can be recharged up to 500 times when fully or partially drained. Package include: 2pcs 18650 4000mah rechargeable battery+18650 charger. High energy density, long life battery. Charges 1 or 2 batteries simultaneously. With overcharge / discharge protection function that you can use it without worry. Durable in low and high temperature operations.Fit for camera, watch, calculators, flashlights, etc.