This PALM micro USB chargeable battery fits snugly and discretely in your hand. It's battery is 550 mAh, with a LED airflow indicator. The juice chamber is also visible to maintain your levels. No button to activate, it's automat with inhalation, and fits all herb cartridges universally, it even includes two ring adapters. Aluminum alloy housing, dimensions are 42x55x12.8 mm. Available in other colors too. Designed in California, made in China.