The new Tenergy 13777 18650 button top battery is stronger and more versatile than their previous 18650s. With an astoundingly high capacity you can use this battery for longer periods of time or with higher draining devices. It offers a 3.6 voltage, an ultra-high capacity of 3500 milliamp hours and comes with a built-in protection circuit. This protection chip is found at the end of the battery and will protect your cell against over-charging, over-discharging, and several other damaging features. The protective chip is extremely slim and will still fit into your standard electronic devices. It can be recharged over 300 times and the ultra-high capacity and long lifespan makes this battery perfect for laptops, tactical flashlights, and so much more!