Amazon.co.jp: Artec 3ch Powered Monitor Speaker PMA-3 : Musical Instruments,Amazon.com: axGear Computer 3.5mm Speakers Led/Volume Control Powered by USB for Laptop : Electronics,Amazon.com: axGear Computer 3.5mm Speakers Led/Volume Control Powered by USB for Laptop : Electronics,Amazon.com: axGear Computer 3.5mm Speakers Led/Volume Control Powered by USB for Laptop : Electronics,2x 3.5