Brass Knuckles Battery

Brass Knuckles battery is designed to utilize concentrate oil cartridges. Brass Knuckles vape pen battery features variable voltage and preheat mode. It works like a regular vape pen battery with single button operation settings: 5-clicks will turn on or off the battery, 2-clicks will activate the preheat mode for 10 seconds and 3-clicks will switch the voltage, LED light will change the color according to the voltage settings: Green - 2.4V | Blue - 3.2V | Red - 4.0V.