The Cookies battery is packed with power. This diminutive device has a super strong 900mAh battery and gives you 5 heat settings (1.8-3.8V) to choose from. Hook it up to a 510 cart for using or the included micro USB-C charger for powering up. Turn it on or off with 5 quick clicks of the button and preheat by holding it down for 3 seconds. It also alerts you of battery life by flashing green (high), blue (medium) or low (red).