Etekcity UltraFire 18650 4200mAh 3.7V Lithium-Ion 4200mAh 3.7V rechargeable battery

UltraFire 18650 4200mAh 3.7V Power when you need it
If you have an UltraFire® flashlight or other device that requires an 18650 battery, this 2-pack will ensure that you always have a battery ready when you need one. Keeping charged spare batteries on hand is the best way to get the most use out of your flashlight, and this set of four batteries makes it affordable and convenient.

High-performance and long-life
These UltraFire 18650 batteries operate at 3.7V with 4200mAh capacity. Built to last, they can be recharged hundreds of times and last for hours on each charge.