The updated ARB-L18-3400U V3 USB-C Rechargeable 18650 Battery includes a built-in USB port for convenient charging without the use of an external charger, although one may be used if preferred. The anode circuit is securely housed in steel, providing additional protection against potential short-circuits caused by impact or collision thanks to the fully-wrapped construction. Note: This item is packaged and priced as one unit - one battery . Shipping Note: Lithium ion batteries are considered "dangerous goods" per US transportation regulations and can often only be transported via ground shipment. Orders containing loose batteries will typically take much longer than predicted to be delivered. Delivery times of 14+ days are not uncommon.