How does a Superpass 2 work?

I might buy one off ebay 25$...

Does it work well with emu, homebrew, etc?

Here's the link:

http://cgi.ebay.com/NEW-SuperPass2-S...QQcmdZViewItem

PLEASE no one buy it. For me, a newb at hb and ds emu, it's this or datel's crap.

And it says compatible with supercard. Do I NEED supercard to use the superpass?

PLEASE help... I muuuussst use Kid Icarus NES on my ds...PLEAASEE?

I need to know so I know if I must sell my Chrono Trigger...