They're portable stereo speakers that require no batteries or external power, and they'll fit in your purse. Perfect for the office or when traveling, these speakers are very light weight. They open clamshell style, like a mobile phone, and snap shut when not in use. The speakers can be connected to any CD or MD player via a gold-plated mini-stereo plug, they weigh 127g and have dimensions of 114x70x42mm. The speakers are full range, 50mm units with a maximum input of .5W into two channels and impedance of 8 ohms.