This vivacious Blue EGO battery will never fade. The EGO battery is a beautiful deep blue with a slight metallic finish. Take it with you on the go and see how the sunlight changes the blue color to a lovely indigo hue. Our Premium EGO battery lasts well over 800 puffs on just one charge; that's four times the battery life of your traditional Ecigarette. Our Premium EGO batteries are exclusively designed to fit our cartomizers, the first of any EGO in the industry to be compatible with cartomizers! The EGO batteries are .5" in diameter, 3.5" long without a cartomizer attached, and slightly heavier than your traditional Ecigarette. All of our EGO batteries have a newly developed rubberized matte finish, making them easy to grip, smooth, and comfortable in your hand.