Mini 1000 mAh Battery Extender and Mobile Power Station for iPod; iPhone 1G, 3G with (White)
I bought one, it came without instructions. When I pressed the test button it had three blue lights. Plugged it into my iphone to test. Blue lights went out and device no longer would take a charge. Luckily it didn't destroy my Iphone. I threw it away after one hour. Don't buy.