The JLab Audio MiniBlaster for iPod nano is a portable speaker system into which you insert your iPod nano, and out comes some really big sound. The small device has the same shape as the iPod nano, except it's about an inch thicker. Using either four AAA batteries or the included AC adapter, the MiniBlaster's two 40mm mylar cone drivers are powered by .5 watts per channel, but crank out a remarkable amount of sound.
Build quality is good, and that 450Hz to 20,000Hz sound spectrum the company says these drivers are capable of is probably an honest spec. Of course, the laws of physics won't let speakers this tiny crank out bass much lower than 450Hz, but the sound coming out of the speakers, while lacking earthshaking bass, was still clean, well defined, and pleasant.
What about volume levels? How loud will they get? Well, holding the unit about 2 feet away from my face, the music was loud enough actually hurt my ears. It's a kick to hold that much sound in the palm of your hand—this baby has enough mojo to make you wanna dance. All in all, I'd say it's a great product for $49.95. Highly recommended.