Eurekka&reg; Black Leather Case with Bluetooth Wireless Keyboard for Apple Ipad Ipad2 Ipad3 Ipad4 Specially designed for iPad 2,3,4 Generation 2 in 1, it can both as a iPad case and a keyboard Continuous standby for 100 days, if you use 4 hours everyday that you can use 20 days Built-in Lithium Battery (450mAh) which can last for about one week You can use this keyboard with most devices that have bluetooth or USB adapter