These speakers are a really great little set of stereo speakers. - Even though they're rather cheap, they give great sound quality for the price, and with their power supply being pulled from a spare USB2 port (USB3 is OK too.), you don't have to worry about finding a spare power plug and powering them from a power-adapter, with all the extra hassle that doing so entails.
I'm the proud owner of more than 1 of these speaker sets, and I thoroughly recommend them if you want a decent cheap set of speakers: Just plug the USB lead into any USB2 or 3 port to supply power, and plug the audio jack into the appropriate audio port. (Front panel; or (green) rear port.)
If you want to put on a rave or something then powerful these speakers are not; but if you just want to hear your device's audio - well in my opinion there's no better choice.