Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
The moment it arrived I noticed there was wires hanging out of the battery tester. As I expected it didn't work. On further inspection it was alsp missing half the screws that held it together. So now I have an overpriced cheap case full of foam that refuses to sit in the case. Last thing I will ever buy from Amazon