Detecting MP3 player volumes

Hello everyone,
I'm writing a small program in which I have to detect all the volumes of an MP3 player connected to my computer (in my case it's a Sansa C250, which mounts two separate volumes). I tried using the volume monitor, and indeed it returns me a list of all mounted volumes, but looking at their type - most of them have a hard disk type, even the player and USB memories. On the other hand, the icon show on the desktop for each kind of storage device is different - the player volumes are shown with a player icon, and the USB volumes are shown with USB icon. I would like to know how can I tell the difference between the volume types.

Thanks in advance,
Avishay