The Aspire ESP is adjustable from 5Watts to 30Watts. You can rapidly regulate the Wattage by twisting the rotary knob located on the top of the device. The screen display is located on the front of the Box Mod, which displays the battery power, atomizer resistance, wattage, and voltage. The Apsire ESP is charged with a micro USB cable, which is located at the bottom of the unit. When charging, a red light will appear, and once it is fully charged the light will change to a solid green.