Neotek Iphone 4 4g External Battery Charger Case Power Juice Pack Air Ultra Slim By Coolshop (Be aware of imitation and only purchase from Coolshop to avoid product of less quality and battery capacity) Charge Your iPhone 4 for 5~6 Hours additional Talk Time 100% new high quality (OEM), never used, Full Body Coverage Protection for Your iPhone Input:12-24V;Output:5V 500mA 1900 mAH capacity Built-in IC chip and safety fuse to protect your iphone being over charged Ultra slim, low profile, light weight/ rubberized surface for luxury touch and easy handling