The cd played once the battery was leaking the mp3 works the cd spins does it need those batteries because i used the battery pack  well thats what going on thanks.This Iriver Slim X iMP-350 MP3 Plus WMA Plus CD Player is a great addition to your portable audio setup. It has a sleek gray design and can play MP3 and WMA formats. You can listen to your favorite AM/FM radio stations using the built-the cdp to 5 hours. It weighs only 2lbs and has a height of 2 inches and width of 6 inches. The iRiver Slim X iMP-350 is a great portable CD player for music enthusiasts.