Keep your Apple iPhone 3G or 3GS working at optimum performance levels at all times with the Emerge Technologies ReTrak iPhone 3G / 3GS Battery Case Charge & Sync. The extended battery case adds up to four additional hours of talk time and 4.5 hours of additional WiFi. The case features an LED light for low-light photographs and videos, and allows access to all ports and buttons. The 2-in-1 wall and car charger lets you power up your phone wherever you are, and features 2 USB ports. The retractable USB cable prevents knots and tanlges, making the ReTrak battery case and charger perfect for travel use.