Cables can act as an antenna, especially if they pass close to a strong source of radiofrequency radiation. One study has suggested that if the cable of a hands free mic passes near the phone's antenna, it can pick up some radiation and transmit it to your ear. Our ferrite snap bead is designed to reduce RF radiation in the cable. Made in 2 halves, you simply press it around the hands free wire at any convenient location near the earpiece end. Couldn't be simpler. It is small and lightweight enough to be almost unnoticable, yet powerful enough (50 ohm impedence minimum) to control nasty radiation. These are brand new, top quality and will accommodate wires up to 5 mm (3/16 inch) in diameter. About 1 inch long, grey color. If you are concerned about radiation from your hands free ear mic, this is the answer. Useful from 200-1000 MHz.
I don’t understand why only the lab tests are accurate. I just purchases two SafeSleeve cases and tested them myself with the same meter they use on their website in the promotional video. I made sure there were no other electronics nearby and I had the meter at zero without the cell phone next to it. I did not get the results they show in the video. I tested the phone with and without the case and it did not make any difference. The meter was peaking no mater what, with the flap opened or closed. If the meter is picking up radiation through the case, then my head is too. SafeSleeve is willing to reimburse me for the cases, but I am concerned that this might be a case of false advertising.
Just why Schwann and glial cells appear to be targets of cell phone radiation is not clear. David Carpenter, a physician who directs the Institute for Health and the Environment at the University at Albany, S.U.N.Y., explained the purpose of these cells is to insulate nerve fibers throughout the body. These are electrical systems, so that may be some sort of factor, he wrote in an e-mail. “But this is only speculation.”
A large prospective (forward-looking) study of nearly 800,000 women in the UK examined the risk of developing brain tumors over a 7-year period in relation to self-reported cell phone use at the start of the study. This study found no link between cell phone use and brain tumors overall or several common brain tumor subtypes, but it did find a possible link between long-term cell phone use and acoustic neuromas.

These cases work by redirecting the electromagnetic radiation (EMR) that is produced by phones, away from the user. All phones produce EMR when connected to the mobile network, and the effect of this energy is measured as a Specific Absorption Rate, or SAR: a measurement describing the radiation absorbed by kilogram of tissue. Government regulations in Australia dictate that all phones in Australia must emit a SAR less than 2 W/kg under the worst case scenario, and while all phones comply, most modern phones emit, at most, only half of this safe level, or approximately 1 W/kg.
I did a lot of research prior to purchasing and came down to this one as the best/most tested and proven option. Happy with the cover. I don’t have a way to actually test the efficacy of it but it’s a quality product otherwise. I haven’t dropped it but there’s enough room around the edges that it seems like it would have a good cushion to blunt the impact when I do. I’d recommend trying it if you like the looks of It.
So, what types of RF are these cases intended to block? If they block the frequency being used by the phone than if the blocking is complete the phone won’t work. If it’s partial than, as noted by the FCC and related in the article, the phone may attempt to compensate for the weakened signal by increasing it’s signal strength, thereby emitting higher levels of radiation itself, and reducing battery life in the process.

The studies are notable for their sizes. Researchers at the National Toxicology Program, a federal interagency group under the National Institutes of Health, tested 3,000 rats and mice of both sexes for two years—the largest investigation of RF radiation and cancer in rodents ever undertaken in the U.S. European investigators at the Ramazzini Institute in Italy were similarly ambitious; in their recent study they investigated RF effects in nearly 2,500 rats from the fetal stage until death.
One of the studies reports that male rats exposed to very high levels of radiofrequency radiation grew tumors around their hearts. Female rats exposed to the radiation didn’t, and neither male nor female mice showed obvious health problems in a second study. Neither study turned up clear evidence that radiofrequency radiation causes brain tumors, although the researchers are continuing to investigate. The studies are drafts that haven’t yet been reviewed by outside scientists.
Thus far, the data from studies in children with cancer do not support this theory. The first published analysis came from a large case–control study called CEFALO, which was conducted in Denmark, Sweden, Norway, and Switzerland. The study included children who were diagnosed with brain tumors between 2004 and 2008, when their ages ranged from 7 to 19 years. Researchers did not find an association between cell phone use and brain tumor risk either by time since initiation of use, amount of use, or by the location of the tumor (21).

The frequency of radiofrequency electromagnetic radiation ranges from 30 kilohertz (30 kHz, or 30,000 Hz) to 300 gigahertz (300 GHz, or 300 billion Hz). Electromagnetic fields in the radiofrequency range are used for telecommunications applications, including cell phones, televisions, and radio transmissions. The human body absorbs energy from devices that emit radiofrequency electromagnetic radiation. The dose of the absorbed energy is estimated using a measure called the specific absorption rate (SAR), which is expressed in watts per kilogram of body weight.
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