The Beretta is a very cool new and advanced battery which can flip between auto or manual modes! Just clicking the battery quickly, 5 times, and it will switch modes, with the light flashing to show that it's been changed! Perfect for both new and advanced e-cig users alike, boasting incredible performance with easy to use features. Additionally, the Beretta features a handy bottom dial that adjusts from 3.3 to 4.8 volts, providing optimum control of vapor output and temperature. Its large 900mAh capacity provides long-lasting vaping power. Compatible with all of our 510, EGO and Crystal Vision atomizers, cartomizers and clearomizers, the Beretta also comes with a 510 to Ego adapter, so you can use it with your existing Ego charger! The Beretta offers an outstanding compromise between smaller units and larger, heavier batteries. It balances well in the hand and has a sleek, stylish look sure to catch the eye.