UKETA Smart Screen 510 Thread Cart Battery - KVB00181. Battery Capacity: 650mAh2. Variable Voltage: 2.8v-3.2v-3.6v3. Use: Quickly press the button 5 times to turn ON/OFFQuickly press the button 2 times to preheat4. 15s preheat mode5. Support OEM, easy to make your original design and packaging