In 2007, our track lighting in our kitchen suddenly stopped working. This was an IKEA light fixture...so the quality obviously wasn't meant to last. I checked the transformer, and found that it was no longer putting out the proper voltage. I checked with our local lighting store, and they quoted me $100+ for replacement of this exact same transformer. I asked if they were serious, and they told me that they were. So I left the store and went online. I found and ordered this unit from Pegasus to replace the original transformer. It worked great...for a while. Now four years later (2011), that replacement unit has failed, and I have once again ordered another to replace it. That transformer was causing the lights to flicker on and off after continuous usage. Replacing it with a new transformer has done the trick...at least for now. This product appeared to be identical to the previous one I was sent from Pegasus in 2007 on the surface, but I can't comment about anything non-superficial. Time will tell if I will get more than four years out of this one. That being said, this is a fairly inexpensive transformer, and one which has seen a lot of use in our house. It's hard to be too critical, especially when there's always the possibility that this fixture is just prone to burning out transformers...it's on it's third one after all.
Anthony: Usually you will need an LED driver (http://www.pegasuslighting.com/led-drivers.html) for LED lighting. However, if you are using, for example, 12-volt LED light bulbs in a 12-volt lighting system then this transformer would work.