Overcharging protection board to prevent overcharging and short circuit Discharge cannot be achieved through the protective board (as the protective board will limit the discharge current) Please charge in a timely manner when there is no power to avoid power loss. !!! Be careful not to place your fingers and hair close to the air intake, and keep away from combustible materials during charging. note: The factory batches are different. If there are slight differences in the appearance of accessories, it will not affect the use of the product.<br><br>Battery 21700x2 4000mAh 7.4v Electric regulation: 30A, adjustable speed, violent start Battery: Lishen 21700 High rate battery 40A discharge Charging: Type-C 15w fast charging supports Qc protocol Material: plastic colour: Black<br><br>Package Contents: 1 x Turbo Jet Fan<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.