Love love love these.  Truly hypoallergenic.  I have the most sensitive nickel allergy, and recently bought earrings that claimed to be nickel free but still made my ears blow up.  These, however, I am able to wear 24/7 with no issues.  I love the variety of sizes, and they're so bright and sparkly! I have three holes in my earlobes, and I currently have in the smallest three sizes, which is good for casual wear.  The backs are tight and have never fallen off. So, so happy!