The listing, Sony Portable Speakers has ended.
I used this speaker set at my job in a warehouse, but had to get something a lot louder for listening via my cellphone, the cellphone sound output isn't as strong as my MP3 player was. The speaker sound is pretty good when amplified, but the cord is only 10" so you might want to get an extension at Radio Shack or whatever.
* Single chassis, dual speakers with 1 watt per channel x 2
* Compact, foldable design permits easy transport wherever you take your portable music player or digital voice recorder
* 1.3-inch neodymium-magnet drivers produce high energy output for greater speaker movement, power, and sonic accuracy
* Magnetically shielded so the speakers will not disturb images when close to a TV or monitor
* Works for 24 hours on 4 AA batteries (not included); also works as a passive system driven by your portable device (no power required)
* Product Dimensions: 9.8 x 3.8 x 1.8 inches ; 8 ounces