There is a lot of snake-oil being sold, and fortunes are being made, off of good people wanting to protect themselves from cell-phone radiation exposure. But, there is an even bigger fortune being made off of purveyors of "safe" technologies, vaccines, practices, etc. Reducing your exposure to high frequency radio is a very good idea. So who do we believe...?You can't really avoid EMF radiation these days unless you move to the country (which I have), but a clear understanding of how radio waves work is helpful for putting your mind at rest.The intensity of radiation emanating from a source, whether it is sound waves or electromagnetic waves is always subject to the "inverse-square-law". That is, "distance is your friend". Double the distance and you cut the intensity by a factor of four! So, unless you are making measurements within the "near-field", or Freznel zone (this is why I completely distrust ultrasound being used on little babies) where "nonlinear effects" prevail, the intensity will diminish four times each time you double the distance. This is a basic principle of physics. Side comment...ultrasound can generate destructive "supercavitation". That's why it is used to dissolve kidney stones and why I distrust its overuse in clinics.The intensity of cellular telephone EMF is also affected by "directivity"...the higher the directivity (or focus) the more intense the field and the deeper the unpredictable, nonlinear, Freznel zone. Cell phone are designed to produce a non focused radiation pattern...that way they will perform reliable when you hold the phone in any position. Yet their short wavelength also implies a greater susceptibility to, what antenna designers call, "constructive interference" or greater directivity! Confused yet?Upshot...these protective devices and patches could actually intensify EMF intensity in one direction! Not good. There should be serious, third-party testing on these gimmics in order to derive objective data. Until then I would recommend a plug-in headset with a 36" connecting cable, or a hands-free mic/speakerphone when making long calls.