Portable 1900MAH High Capacity Extended Battery & Protective Battery Case for Iphone 4 4S (Fit All Models Iphone 4 4S) Retail Packaging Matte Blue Doubles battery life for iphone 4 4S(all models) High capacity 1900MAH battery hidden inside ultra thin durable case Sync & Charge simultaneously Four LED power indicator Slim fitting and nearly weightless design minimizes any added bulk