We use a device called a frequency generator, which generates the frequency range of the brain 1 – 44 hz. We attach it to the sensors so we can benchmark how accurate the FocusBand hardware is performing. For example, we setup the frequency generator to generate 8hz onto the FocusBand headset sensors. We then test to see if the output inside the FocusBand app shows 8 hz on the screen. Our tolerance is .25hz, 1/4 of 1 hertz.