After purchasing over 15 diffuser necklaces from many different companies, I can say that AromaRain's quality is by far the best. I have never had issues with the lockets chipping, tarnishing, changing colors or causing skin irritations as I have with the rest. Highly recommend and will only use them from now on. I can also say that I was very impressed with their USA customer support. Thanks for taking the time to make such great products AromaRain.