4Pcs 18650 2800mAh Li-ion Rechargeable Battery, Mini Butterball 3.7V Li-ion Batteries with Charger for Flashlight Headlamp 4Pcs high performance18650 3.7V 2800mAh Li-ion rechargeable battery with a battery charger. Safe and environmental friendly. High energy density, long life battery. Note: it is button top battery, will not suitable for some device which use flat top battery 100% Customer Satisfaction Guarantee - 30-day money back.