Anybody know about this exo terra light cycle unit?

I ran across this product, but cannot seem to find any reviews or detailed info about it. :confused:

http://www.exo-terra.com/en/products...cycle_unit.php

It says it simulates dawn and dusk, but I am curious if both bulbs are cycled simultaneously or if they are cycled individually.

Say for instance I wanted a day/night cycle, would I need 2 units and 4 bulbs? (2 day bulbs in one unit and 2 night bulbs in the other)

I have done lots of searches but have not found this info yet.