Volcano speakers erupt with a mighty sound! Designed with the traveler in mind this powerful speaker is also amazingly compact. With a slight twist the volcano speaker features a bass expansion system that gives these bad boys some extra oomph! The speaker also features a rechargeable battery that can be powered by a USB port. These are sold as a single speaker but can be connected together to really get the volume cranking. Compatible with laptops, Ipods, and any other device that features a regular audio connection. Great sound, amazingly compact and a great price. How could you say volca-no???