His heat source is not that of a bulb...when I bought his encloseure there was an option to have a heat "panel" installed...the heat panel is white and attached to the top of the enclosure nicely...the cage is made of a heavy composite material and is only glass on the front..Ill try to find the site i bought it from but at the time it seemed like a "top of the line" setup?? Theres not really anyway to install an uth with a setup like this--