It's the best for indoor gardening. Great spectrum, long life, plants love it, less heat than a 400W HID, and Philips began the CMH thing. They are still at the top.
I bought a 4200k bulb supposedly. But I look at the box and bulb it's a 3100k and it's used. I see why there is no return thief. The 4ks have mw on them. Buy from stores or phililps site.