Great LEDs, I used them for my science project. I was trying to figure out which part of the visible light spectrum was best for growing plants, and these did the trick. I found that the blue worked the best. My only complaint, though, is that they are clear, and don't come with any description out of the box, which means you cannot immediatley identify what color they are out of the package. You have to light them up, and then organize them. No biggie though. Great LEDs and very bright when running off 3.6 volts. Also very energy efficient, I had 8 of these running off of two AA for a grand total of over 200 hours, and did not drain the battery very much.