Q-ULTRA designed with 0.69" OLED display screen, which indicates the battery level, coil resistance, wattage value, puffs count, vaping time counter. Puff counter gives you a certain number to hold a standard to vape. Hold the fire button and "-" button together to set the puffs to zero. You can adjust power among 5W-40W by pressing the "+" or "-" button. The Q-ULTRA features refillable pods with replaceable coils, allowing for up to 4.0ml of stored E-Juice or nicotine salts.