My daughter (recently turned 10 yrs old) had begun using this and unfortunately the new teething puppy had decided to use it as a teething ring.  My daughter felt this was the only mask and snorkel she felt comfortable with so we decided to get another one to replace the previous.

I bought this mask for my 6 year old daughter.  We loved it for the first few days.  Unfortunately, it shattered when she jumped into the pool.  Fortunately, none of the glass shards injured her.  I was really surprised that it shattered like that.  I'm not sure whether it was a defective mask or whether they are designed to do that...I can't imagine the latter.  It's real glass, not plexy or plastic, so just be warned that it could injure your child if it were to shatter like ours did.