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.
These 5 black silicon coasters are well made and look great. They have a small slip around the edge meaning any slight spills are not going to drip onto the surface you're protecting. Being silicon they should last for years.