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.
I bought product to keep in my vehicle in case I experience some unknown emergency. So I have not opened it or had the opportunity to us it. But, trusting it will work as you described it would. SO Currently, this is my reason for rating at a 1 star rating.