Battery fits Apple iPod nano 3rd Generation 4Gb and 8Gb series-450mAh High Quality, high capacity, light weight rechargeable DC Lithium Polymer 450mAh battery. Longer battery life than the original battery that comes with the PDA. Best replacement for the original Apple iPod nano 3rd Gen (616-0337) 4Gb & 8Gb series battery pack. No memory effect. Can be charged or discharged as needed without loss of capacity. Overcharge protection, with built-in battery life microchip + 6 months Manufacturer warranty