eGo AIO Battery by Joyetech come uniformly as one with the only detachable part being the top cap where you change your coil and fill your tank. The tank includes leak-proof and child-proof features such as a pressure sensitive twist cap where you top-fill your e-liquid. Also as an innovative bonus the drip tip has a built-in spiral to continuously cool your vapor before it reaches your lips. It is highly recommended from Joyetech to not fill past the "MAX" line indicated on the tank to prevent overflow when the top cap is screwed back in place. Easily rechargeable through a micro USB port the tank even illuminates itself in a colored light when the battery is charged. The colored backlight can be alternated between seven different choices (red yellow green blue purple white or indigo) which is easily accessed by pressing and holding the firing button.