Our Milky Way batteries are button activated and 510 Thread. 350 MaH. Adjustable from 3.3 volts to 4.8 volts & includes a USB charger. It is best to use our batteries at 3.3-3.6 volts. Do not exceed 4 volts as you may burn the coil of the cartridge. Directions on how to use this battery: Press 5 times to turn on and off. Twist at the bottom to adjust the voltage (temperature at which the device operates) Charging instructions: red light means charging, green light means fully charged. Fully charged in 1 hour. Please let the battery cool down between uses as over heating can cause your cartridge to leak.