Features a protected, cartridge drop-in design / Fits most 510 thread cartridges (included cartridge is non-functional and for merchandising purposes only) / Powered by a high-quality 300mAh lithium-ion rechargeable battery core / 3-LEDs indicate battery life and power settings / Four (4) power/voltage settings (2.4V, 2.8V, 3.2V, 3.6V) / USB magnetic charging port + cable / Compatible with Base Charger and Rover Case