mophie juice pack case and rechargeable battery for iPod touch 2G, 3G (Black) Power on-the-go - Charge your battery anytime with the Juice Pack Convenient Holder and Cool Design -Rubberized, soft-touch finish offers a secure andcomfortable grip on-the-go. Intelligent Power Distribution - Smart Battery Technology instructs the iPod Touch to always use the Juice Packs power first. Unique Pass-Through Design - While charging the Juice Pack with the USB mini cable 4 Light LED Battery Status Indicator - There are 4 LEDs on the back of the Juice Pack. Simply press the test button