I bought a set of these little beauties from a Cotswolds camping shop for £30. They are truly brilliant compared to many of the portable speakers you can buy for more money. They are powered by an internal rechargeable battery, charging via USB connection (you can use of those mains plug adaptors rather than your laptop or PC) and takes an hour or so. Play time when charged about 4 or 5 hours. Volume control actually works and the top level is pretty loud, distortion at max volume almost non-existent - depends on your MP3 player equaliser settings. Bass good, treble clear. Cables very fine but seem robust - they retract into the body of the speaker on a spring loaded thingy, pull them out and then tug and they zip back inside. I love things like that. Speakers good for either rock or classical music which is an achievement in itself. Really good value.