Made by Hagen and marketed as a Terrarium lamp controller. I have to say that Hagen is missing out on a lot of business because they aren't also marketing this as an aquarium lighting system!
I have the dual controller (2 x 40W) on my 60 gallon tank. My prior tanks all had home made canopies with the Hagen Glo-Mat external ballasts. The Exo-Terra units have the same end caps as the Glo-Mat units and the model I purchased is T10/T8 compatible.
What makes this unit better than the Glo-Mat units is that it has a timer built in and it dims the light cycle in and out.
Light cycle is can be set to 10, 12 or 14 hours via a switch. There is no clock to set, the timer starts its cycle timing from the time you turn the power switch on and stays that way until you turn it off or there is a power failure.
The dimming works amazingly well with no flicker. By my count there are 10 two minute "steps" into the cycle and back out at the end of the cycle.
There is a test switch to verify that the dimming circuits are functioning correctly as well as power, day (cycle on) and night (cycle off) indicator lights.
Back when I used the Glo-Mat ballasts on timers the fish would always jump when the lights went on or off. With the Exo-Terra light cycle unit they don't even flinch because they are eased into and back out of the bright light nicely.
Now if Hagen would only include bulb clips with the unit and create packaging for aquarium use more people would know about this great product!
The link to the light cycle unit on the Exo-Terra web site: http://www.exo-terra.com/en/products...cycle_unit.php