Mini Fold-Up Speaker System for iPod MP3 Compatible with iPod MP3 player or any audio player with a 3.5 mm jack. Enjoy high quality stereo sound with these compact travel speakers. 1 W + 1 W output power. 200 Hz - 12 KHz frequency response 50 mm speaker, 4 Ohms. 7-inch 3.5-mm cable length (approximate) Power input: four (4) AAA batteries or AC adapter (DC 6V, 350 mA)