This is a really nice power supply. It's a switching DC supply so its small and light and efficient. It is thin so it fits in power strips without blocking other outlets.
The output is regulated so you'll get a steady 9V up to 660mA of current draw. 2.1mm barrel jack, positive tip. There's a red LED 'pilot light' that will let you know its plugged and powered and the new ones I got now work in the US (120V) as well as Europe (220V) !
Great for MIDIsense, YBox2, Boarduino, clock kits and Arduinos! Not OK for x0xb0x...this is a DC supply not AC. This supply also doesn't work that well with Fuzeboxen, its just a little too noisy and that will show up in the video out.
Dimensions (wall wart):
Cable length : 147cm / 58in
Cable Diameter : 3.5mm / 0.13in