Uses 1-CR123 battery, not included.

It is powered either by the remote commander, or I "THINK" by certain Nikon-brand flashes with built-in slave capability.  The owner's manual is available online.  As far as I can tell, it is not powered by ordinary wireless optical flash in the manner of a traditional slave flash.

I also believe it can be used with Nikon film cameras having TTL capability-again, refer to the online owner's manual.

Selling AS-IS, no returns.