Since July 2007, third-party battery replacement kits have been available at a much lower price than Apple's own battery replacement program. These kits often include a small screwdriver and an instruction leaflet, but as with many newer iPod models the battery in the first generation iPhone has been soldered in. Therefore, a soldering iron is required to install the new battery. The iPhone 3G uses a different battery fitted with a connector that is easier to replace. The iPhone X features a different battery, with two battery cells, and the adhesive pull tabs are adhered to the sides instead of folded over the top, therefore making repairs a little more difficult than before.