Battery for Apple iPod Nano 4gb a1137 2gb 1gb 30-Day Money Back Guarantee & 1 Year Replacement Warranty! Capacity: 350mAh 3.7V (1.3 WHr) Dimensions: 39.37 x 23.36 x 0.38mm (LxWxH) Condition: Brand New - 100% OEM Compatible Type: Li-Ion