I have a Zen Xtra 30GB, but I am guessing the charger is the same.
I'll read what it lists on the charger's sticker:
Switcher Adapter
Model No: TESA3-0501500
Input: 100-240V ~ 50-60Hz MAX 0.24A
Output: 5V -_ _ _ 1.5A
(The weird thing I drew in inbetween 5V and 1.5A is supposed to represent a solid line on top of three shorter lines)
Hope this helps.