Looks like a ceramic metal halide lamp. You can read about those on the web or search here, newish technology but widely available. Will be suitable for use as a plant light, but the marketing as a premium product suggests that you won't like the price ;)

150W makes it suitable for growing areas of approximately 5-15 square feet, depending on the light level required, just as a 4x40W fluorescent lamp would be. Little to choose between the two setups for total light output and efficiency, choose which works best for size and possibly aesthetics.

Thanks, shrubs, for your helpful assessment. I'm dreading the price too... Do you think it would fade out a carpet really badly in a living area?

Do you think it would fade out a carpet really badly in a living area?

Almost certainly.

Low UV metal halides are increasingly available, actually normal metal halides with filters built into the bulb to cut out most UV. , but any metal halide that doesn't explicity make this claim is going to fade anything with dye in it. You could also look for UV-blocking perspex which you could place in front of the lamp shield (not too close!).

Well, guess I won't be buying one - the dealer wrote back and said, "I regret to tell you that we are no longer a dealer for this product. They have not returned any phone calls or emails in the past few months." Meanwhile, I had emailed the manufacturer and have heard nothing.

Caveat emptor.