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