The Exxus Slim mAh 510 Automatic Battery by Exxus Vape is a streamline, simple, pen style battery. Its straightforward, uncomplicated design make the Exxus Slim an easy addition to many tanks on the market. Adding to its ease as a battery mod is the fact that is has a 510 thread attachment port. That threading count is a fairly common industry standard. As an automatic battery, a few short inhalations starts the priming process and the device reaches vaporization quickly for an ideal session.