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.
It worked as I expected (hair dyeing) but quality isn't fantastic (it's cheap plastic). Hope it doesn't release any chemicals in the long-term. There was no product details like materials and country of origin.