The Limited Edition SLIM Battery pairs best with the Limited Edition ConNectar or any 510 threaded cart! With a 400 mAh battery with three different power settings [Low (2.8v), Medium (3.4v), and High (4.0v)] the SLIM battery allows you to pick the setting thats right for you! With a double tap Pre- Heat function and a micro USB charger this is the perfect discreet on the go battery for you!