The Leaf Buddi TH-320 Mini Box is a strong variable voltage 650mah battery that is both compact and powerful. The TH-320 Mini Box is completely compatible with all 510 cartridge tanks. To use the TH-320 Mini BOx simply press the fire button 5 times to turn the device on and off. The TH-320 has a preheat option that can be accessed by pressing the fire button 2 times. To change the voltage on the TH-320 Mini Box just press the fire button 3 times and the LED indicator lights will tell you what voltage it's set on; Green is 3.5V, Blue is 3.8V, and Red is 4.2V. Never charge the TH-320 Mini Box device for more than 4 hours at a time. Get the amazing Leaf Buddi TH-320 Mini Box from RichMountainDist.com today.