I personally have found all those to be nothing less than garbage for bearded dragons... I bought a fixture from Walmart ( or home depot for the MVBs) for less than $11. Remove the lens, and using wood screws, adhere it to the back wall, then thread the cord out of the enclosure, and plug it in... took me like 5 minutes all total.
The Walmart fixture is made by Lights of America...

Janie