XM Radio is a satellite based radio system. It requires a monthly subscription fee for reception.

This Pioneer Inno XM2Go Portable Satellite Radio and MP3 Player  is the complete entertainment package. It's a satellite radio that lets you listen to live XM broadcasts at home, on the go, and even in the car (car kit sold separately). Store individual songs or entire blocks of XM Programming and listen to them anytime you'd like. Or you can Upload some of your favorite MP3 and WMA files, and create playlists that include MP3s/WMAs and the songs you've recorded from XM.
The Pioneer radio offers the long-awaited combination of MP3 and live XM Satellite Radio reception in a sleek, handheld device. The wearable radio delivers XM’s over 170 Digital radio Channels of commercial-free Music and premier sports, news, talk, and entertainment programming live and nationwide. Has 1GB of memory storage for MP3 files, WMA files, and XM programming, to hold up to 50 hours of content.