My biggest issue with this product for chameleons is that chameleons are not (for the most part) a desert animal.
I prefer to provide separate areas for UVB exposure and basking.
The Zoomed Repti-Sun 5.0 linear tube is the tried and true, fail-safe, proven winner. In some cases the 10.0 is preferred (ie: denser screen, fixture is positioned at a distance from enclosure ... etc.)
I use a four foot double fluorescent tube fixture (intended for a shop or garage) that runs about $8 at Home Depot, with one 5.0 tube and one full spectrum plant light.
A separate basking area is created in my enclosures with a simple $7 shop light and a regular incandescent household bulb. The wattage of the basking bulb is determined by where it is positioned and the temperature created. It is easily adjusted by repositioning the fixture or raising or lowering the bulb wattage.
5.0 tubes are available from LLL for $13 and change.
5.0 tube: $14
plant light $8
house bulb$1
fixture $7
fixture $8 Total $38.00 (plus shipping for light from LLL)
Add $8 more for another basking light and you've got 2 enclosures covered ($38.00 + $8.00 divided by 2 = $23.00 per 2x2x4 enclosure)
-Brad