This replacement battery is compatible with Apple iPhone 4S and has a capacity of 1440mAh. It is designed to provide a reliable power source for your device. With a voltage of 3.8V, it ensures that your phone stays powered for longer periods of time. This battery is brand new and is a perfect replacement for a worn-out battery. It is ideal for those who are looking for an affordable way to extend the life of their device. Whether you are a heavy user or just need a backup battery, this replacement battery is a great choice.