Use your headrest whenever you have 10 -15 minutes to relax watching TV, at the beach...feel the difference!
Caveats, Cautions and Warnings: Since this device has a strong magnetic field, it should be kept away from magnetic storage media such as computer discs, magnetic tapes or instrumentation devices such as watches, pacemakers and/or automatic internal defibrillators. If you use any of these devices, do not have them in close proximity to the strong magnetic fields of the headrest. The magnetic headrest is not recommended for driving or overnight sleep, and should be avoided if you are pregnant or have a pacemaker.
One size fits all.