Griffin Evolve Wireless Sound System for iPod. RMS rated power: 12 W, Frequency response: 120 - 2000 Hz. Battery type: CR2032, Battery voltage: 3.7 V, Battery life (max): 10 h. Dimensions (WxDxH): 400 x 140 x 190 mm. Colour of product: Silver. Compatible products: -iPod Touch -iPod Classic -iPod nano (3rd generation) -iPod with video (30GB, 60GB, 80GB)