Toke Buddy Variable Voltage push button vape pen battery. The knob on the vape battery's tip lets you change the voltage between 2.0 volts and 4.0 volts. The push button on the preheating unit activates it. The Toke Buddy Twist VV 510 Thread Vape Pen battery has a straightforward design and plenty of power to handle even the heaviest concentrates, so if that's what you're after, look no further.