eBags Lifejacket Quick Charge Battery (4000mAh) Anodized Aluminum This item is unable to ship to AK and HI due to the lithium batteries. Super-slim design stores easily in any type of bag or pack - Enough stored power to recharge nearly any device. Never be without power again 4000 mAh capacity at 3.7V(33.3Wh) Ultra-slim Lithium-Polymer battery One USB output port delivers 1A output to charge your devices with more than 90% output efficiency