Craig Amplified Travel Speakers Great for PSP or iPod. Requires 4 AA batteries (not included). Fold up for storage. Open up to jam! On-off power button with LED power indicator. Input: 3.5mm Stereo Jack. 3.5mm Connector included. 1.25" Full Range Drive x 2. Impedance : 4 ohm. Frequency Response: 100-20000Hz. Stereo Sound Compact Speaker. Peak Power Output: 10W.