It's the cable with the mini end that goes into the mustang and the regular sized end that goes into your computer. I think it's just call a "mini usb cable". You could be able to get one anywhere.
Strange, yours didn't come with one?? If yours is a Mustang III, it should've come with a USB cable, and the MS2 Footswitch with it's own mono jack cable.
Yep, it's a generic USB cable. It's also the same cable you'd use if you want to do direct recording into your computer… and there's no latency issues (no time lag between your playing and what you hear from your computer's headphones or speakers).
TW I got mine "used", although it looked brand new to me, still in it's protective wrapping and everything. Also mine came with both the 2 and the 4 footswitch, $224 shipped, so I cannot complain about a missing cord that you can get anywhere for like 5 bucks I'm guessing
If you have an old Blackberry or Cell phone USB cable, it will work. As long as its the older trapezoidal mini USB connector you'll be fine. cameras, etc. too.