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.
The product is what it says. If you are an 80's movie fan like me you might think these things need no skill to use, but they are actually a mechanised 'bump key' device and as such do need to be learned and tuned. That having been said, the tool is useful and functional and was delivered very promptly and in perfect working order. No complaints.