The Slim Battery by Kandypens is a powerful, pocket sized, 180mAh lithium-ion rechargeable battery. The “cherry” end of the battery has LED’s that glow when you inhale or flash to indicate the battery needs charging. It’s also tipped with material to give the battery a stylus function with your smartphone or tablet. There’s no button to activate, just inhale to enjoy your favorite e-liquids. USB charger included.