How to operate a DubCharge:
First you must turn ON the battery by clicking 5-times on the main button. Next, to preheat your cartridge click the main Button 2-times. After preheating, to pull/inhale your 510 cartridge click and hold the main button on the DubCharge Battery. We recommend beginning with the lowest voltage (2.5V Blue). To adjust voltages, click the main button 3-times.