I have used it twice so far and found 1 positve test.
I have used other testers before and I don't like the feeling of "can I really trust it?".
Well I had a false positive in my truck with a rented tool from the auto parts store and I was just about to pull the heads, so I tried this one as soon as it came in and the test WAS NEGATIVE.
I like to have the dual chambers to avoid a false negative, very easy to use, comes with a lot of fluid to test and if you are a weekend mechanic it has clear instructions to use and diagnose your vehicle.
Very satisfied.
If this review was helpful to you click Helpful so others can see it too.