This item is sold as an adult mask (from memory, I do think the packaging states its for an adult), having read the other reviews about it being small, I purchased this for my ten year old daughter.
The mask fits my daughters head well. She already has the straps on the largest adjustment though so there won't be much room for growing.
It seems solidly built so should be able to cope well with the demands a ten year old can put on it. Its a nice piece of kit and works well although I should mention its only being used in the swimming pool.
I would definately recommend to parents who are looking to buy for their child but I would recommend that adults might want to look for another product.