Amazon calculates a product's star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers and factors that establish reviewer trustworthiness.
First time I thought my money got wasted but later on I realised that money was not wasted. The product is nice and delivery was done in 2-4 hr only after order. Easily installed just follow the guidelines.. It correct to use..