Has worked fine for several months. For the price it is a very good product. I only think the clip could be a bit bigger.
A little modification...
The dog is used to the flashing, but you should get rid of the 'heart' because you're going to lose it anyway. I covered the LED in some transparent heavy duty tape to protect it from the wet. It was quite easy. Also the clip should be replaced by something made of wire - it reduces the weight of the thing by a third. The pendant is now the sham of a small name tag and still just as visible.