I really want to caution you to be careful of any "expert" or EMF blogger recommending anti-radiation filtering cases, stickers that attach to the phone or necklaces to "ward off" EMF.  I get it, when I first realized 25 years ago that I was sensitive to electromagnetic energy and then later, when I understood that without a doubt, man made electromagnetic radiation has a biological effect on my body, I wanted an easy fix.  I tried the shielding materials and cases and I just did not feel any better.  Then I bought meters to see if the energy changed and I actually noticed what the California Department of Health now says and it's what the FTC and FCC post warnings about:  "Some shielding materials can make exposures worse". So please, be careful and read on for what you can do to avoid electromagnetic radiation exposure.

The use of "hands-free" was not recommended by the British Consumers' Association in a statement in November 2000, as they believed that exposure was increased.[41] However, measurements for the (then) UK Department of Trade and Industry[42] and others for the French Agence française de sécurité sanitaire environnementale [fr][43] showed substantial reductions. In 2005, Professor Lawrie Challis and others said clipping a ferrite bead onto hands-free kits stops the radio waves travelling up the wire and into the head.[44]
These experimental findings raise new questions as to the potential for radiofrequency radiation to result in cellular changes and offer potential avenues for further laboratory studies. Cancers in the heart are extremely rare in humans, where the primary outcomes of potential concern with respect to radiofrequency radiation exposure from cell phones are tumors in the brain and central nervous system. Schwann cells of the heart in rodents are similar to the kind of cells in humans that give rise to acoustic neuromas (also known as vestibular schwannomas), which some studies have suggested are increased in people who reported the heaviest use of cell phones. The NTP has stated that they will continue to study this exposure in animal models to further advance our understanding of the biological underpinnings of the effects reported above.
A third requirement was for the FDA to create a formal interagency working group to oversee the work and provide input. The purpose of this was to alleviate any perception that the industry was paying for a result, not for the research itself. But the fourth and last requirement was considered by Dr. Carlo to be highly critical: “Everything needed to be done in sunlight. The media had to have access to everything we did.”
In addition to the increased brain cancer risk, in male rats there was also “clear evidence” of a link between the radiation and malignant heart tumors and “some evidence” of a link to adrenal-gland tumors, according to the release. In mice and in female rats, however, the link between radiation and tumors was “equivocal,” or uncertain. The hierarchy, from most to least certain, of characterizations used by the NTP is: “clear evidence”; “some evidence”; “equivocal evidence”; and “no evidence.”Today’s cellphones use higher-frequency radiation that is less able to penetrate animal tissues than the radiation used in the study, the Times reports. Further, since cellphones became popular, epidemiologists have not observed an overall increase in the frequency of brain cancers known as gliomas in humans. 
The exact source of radiation in a cell phone is from the transmitter, a device located near the antenna that converts audio data into electromagnetic waves. The amount of radiation a cell phone can emit is limited by legal restrictions in the U.S., Canada and Europe. Additionally, the average radiation levels of most mobile phones are available to the public, courtesy of the Federal Communications Commission in the U.S.
Wearable tech such as the Apple Watch might as well be called a wearable EMF device. These watches are even worse than mobile phones in that they remain in constant, direct contact with your skin. New York Times columnist Nick Bilton covered this issue in March 2015, noting that constant, low-level radiation from such devices can trigger the formation of cancerous tumors, blood abnormalities, and more.

A full featured desktop or wall mount corded telephone (no microwaves) combined with a special ultra low EMF headset. You get all the benefits of a normal telephone without putting yourself close to the strong magnetic fields associated with the handset, speakerphone, or phone base. The special headset cord is about 3 feet long and uses a plastic tube to carry the sound to your ear. Absolutely no electronics, wires or magnets are near your ear. Cord provides distance from telephone base and traditional handset, convenient mobility, and can be extended up to 15 feet with option extension cord, sold separately (see below). Tested and approved by Less EMF Inc., dramatic field reduction when the headset is used. Although pictured as white, our current stock is a black phone.
Many respected scientists join them. “We found no evidence of an increased risk of brain tumors or any other form of cancer” from cell-phone radiation, says John Boice Jr., Sc.D., president of the National Council on Radiation Protection & Measurements and a professor of medicine at the Vanderbilt University School of Medicine in Nashville, Tenn. “The worry should instead be in talking or texting with your cell phone while driving.”
When turned on, cell phones and other wireless devices emit RF radiation continually, even if they are not being actively used, because they are always communicating with cell towers. The dose intensity tails off with increasing distance from the body, and reaches a maximum when the devices are used next to the head during phone calls or in front of the body during texting or tweeting.
All cell phones emit Electromagnetic Radiation (EMR). Most people are aware of Radio Frequency (RF) (also known as Microwave) signals that connect your cell phone to a cell tower, a WiFi router and Bluetooth devices. These cell phone signals are always on. But did you know that cell phones also emit Extremely Low Frequency (ELF) radiation produced by the cell phone’s internal components?
In the US, a small number of personal injury lawsuits have been filed by individuals against cellphone manufacturers (including Motorola,[28] NEC, Siemens, and Nokia) on the basis of allegations of causation of brain cancer and death. In US federal courts, expert testimony relating to science must be first evaluated by a judge, in a Daubert hearing, to be relevant and valid before it is admissible as evidence. In a 2002 case against Motorola, the plaintiffs alleged that the use of wireless handheld telephones could cause brain cancer and that the use of Motorola phones caused one plaintiff's cancer. The judge ruled that no sufficiently reliable and relevant scientific evidence in support of either general or specific causation was proffered by the plaintiffs, accepted a motion to exclude the testimony of the plaintiffs' experts, and denied a motion to exclude the testimony of the defendants' experts.[29]
In 2011, two small studies were published that examined brain glucose metabolism in people after they had used cell phones. The results were inconsistent; whereas one study showed increased glucose metabolism in the region of the brain close to the antenna compared with tissues on the opposite side of the brain (26), the other study (27) found reduced glucose metabolism on the side of the brain where the phone was used.

So, what do these results in rodents mean for people? Not a whole lot, experts say. “Even with frequent daily use by the vast majority of adults, we have not seen an increase in events like brain tumors,” the FDA’s statement says. Otis Brawley, the American Cancer Society’s chief medical officer, agreed in an interview with The Associated Press. “The evidence for an association between cellphones and cancer is weak, and so far, we have not seen a higher cancer risk in people,” Brawley told the AP in a phone interview. “I am actually holding my cellphone up to my ear.”
I'm glad I spent the money to get this protection. Again, I consider this an "insurance policy" and hope cell phone radiation is over hyped. However, mounting evidence seems to indicate otherwise, so I feel more comfortable knowing I'm taking proactive steps to protect against a possible health problem I and my family might face in the future from long and close exposure to cell phones close to the body and head.
A package for it is sold for 70 bucks that includes a choice from seven different color air-tube headsets in two styles (mono or stereo) with a ferrite bead already installed on the headset wire. A 4th accessory is included as a reminder that radiation is only shielded from the front of the phone when case is closed. The plastic stand enables a user to tilt the phone so that the unshielded sides and rear of the phone aren’t “inline-of-sight” with the body. Cell phone radiation, just as light, travels in a straight line. Being informed and awareness of using a phone safely is the most important aspect of RF Safe’s system of safe cell phone usage with 4 accessories for 69.99.
I received mine yesterday in the mail. I have a Samsung Galaxy Note 3, and I cannot use this sock unless I take the case off. This is one thing I did not know when I was purchasing this material. I am trying it out as stated, however even when I use a rubber case or a very thin case with the sock its very tight to get off. I think the manufacturer needs to allow more room in these and or not state that it fits the larger phones at 6 inch. They should state that without the case it will fit. I am in the first day of walking around without a case, and just the sleeve. Its different, and if I drop my phone I'm in a world of hurt. I like the idea of this, but I was also surprised when the material really only feels like felt. It's not like the RF fabric that I have seen, and hopefully this is some kind of special blocking material as stated. I do like the idea, and I agree that cell phone radiation exist. Ill come back and give five stars if I really notice a difference, however if I drop my phone because I dont have a case I'm going to be posting less stars.
A series of studies testing different scenarios (called simulations by the study authors) were carried out using incidence data from the Nordic countries to determine the likelihood of detecting various levels of risk as reported in studies of cell phone use and brain tumors between 1979 and 2008. The results were compatible with no increased risks from cell phones, as reported by most epidemiologic studies. The findings did suggest that the increase reported among the subset of heaviest regular users in the Interphone study could not be ruled out but was unlikely. The highly increased risks reported in the Swedish pooled analysis were strongly inconsistent with the observed glioma rates in the Nordic countries (24).