To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
There is not enough adjustment in the strap. I adjusted it as large as i could and it was still too small. I had my wife add a piece of elastic to make the strap longer. The fit around the nose is not good. It fits so tight that it can interfere with breathing.