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 had to use these for the first time the other day and they did the job perfectly well! They didn't break, even though my tyres are a rather snug fit in the rims. Apart from the fact that they are non-scratch, another nice feature is they snap together for ease of storage in your tool bag. And they're cheap!