Its a little microchip. If you have a mod that ISN'T Variable Voltage or Variable Wattage...
You can buy a KICK microchip. Then, you use a battery that is 1 size smaller than the tube, with the kick.
So, if your mechanical mod is for use with 18650, you use the Kick with an 18500 battery.
With the kick on top of the battery, you can adjust the wattage/voltage and make your vape mo powerful.
Beyond making your vape more powerful, it REGULATES the battery.
SO, from right off the charger, all the way until the battery dies, it'll be the SAME voltage.
Unlike with just using a regular battery without regulation, which will voltage sag as it drains.