Review on Calibrated ITEQ Brake Fluid Tester Pen With 5 LED Indicators For Accurate Testing Of DOT3 And DOT4 Brake Fluids by Jason Bolden

I tested it in two brand new Brake Fluid bottles and it failed both of them. Each bottle was from a different store. Both bottles were a Prestone Brake Fluid but one was a 50K fluid and the other was a 100K fluid. Both failed, what do you trust. Does Prestone use additives that change the conductivity of the fluid? I contacted Prestone by e-mail and phone and they never replied. Makes you wonder about Prestone as a Company . I have seen others complain about Preston Brake Fluid failing with this tester.