This one is almost identical to the official nook clip-on light:
http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1
I picked it up for my wife recently - it really is almost identical, even uses the same batteries. The LED color is _ever-so-slightly_ different hue than the stella light that I have, but I can't say if one is really better than the other.
By the way - buy the batteries in bulk to save tons of money. I went a little overboard:
http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1