Masione Replacement Battery for iPod Nano 4th Generation 8GB 16GB 616-0407 With Tools Brand New | Li-Polymer | 3.7 V | 350mAh Compatible with iPod 4th Generation 8GB/16GB This is an internal part and some minimal technical skills are required to replace it Tools are provided to open ipod and replace battery 30 days money back and 1 year warranty