It explained how to remove the above cab brake light and put a backing magnet in the hollow area behind the brake light

We moved up to the country with many dead areas with no signal

All that being said, it does what it says it does and gets me usable signal in otherwise useless areas.

Recently I took a vacation to Arizona and thru the deserts of Nevada thru those desolate areas I found less than acceptable cell phone service, go figure

Not much - say ranging from 95 to 82db in the app I downloaded, but probably enough to make a difference in receiving or not receiving data/calls in sketchy areas.