@heisenberg34
He needs to be very care full , they kept adjusting mine also and drove pain up my neck and around the back of my eye ,, I got mine fitted in 2014 , it kept breaking down, and stopped working completely in 2019, I got 2strokes from there adjustment I asked for it to be set back to original settings, there was a blind eye turned t me .. I never had pain in my neck and eye before I got a stroke in 2022 , and another in 2024 ,,

U need to tell ur friend be very careful, I am convinced they don’t no anything about them ..