The Contour 2 cartridge battery is the most discreet vaporizer on the market today. It's compact and curved design fits easily in the palm of your hand so you can vape your favorite oils anytime, anywhere. Simply screw the magnetic ring onto the bottom of your cartridge and insert it into the device. It's that easy! The powerful 650mAh battery features a preheat function, as well as variable voltage so you can choose the setting that's best for your oil. And since your cartridge goes inside the device, you don't have to worry about broken and leaking cartridges. To recharge simply plug in the micro USB cord into a standard wall plug. No need to remove your cart until it's cached. And the window will allow you to view how much oil you have left without having to remove it from the battery. All Contour 2s come with a micro USB cord as well as 3 magnetic rings.