How It Works What's Safe? Compare Products Shield Sham SAR Testing		SHIELD SHAM Shields for blocking cell phone radiation are only partially effective. They only remove some of the microwave radiation and can hamper the operation of the phone. Shields may interfere with proper operation of the phone by shielding the connection between the phone and the base station. This may hamper the operation of the phone and cause the phone to increase its radiation output to compensate for the impaired connection, and it may decrease the range of the phone. Furthermore, even though the shields under ideal circumstances may reduce head exposures by more than 50%, phone radiation may still be substantially higher than the threshold above which biological effects occur. Furthermore they are not capable of blocking ELF radiation. Absorbent shielding materials can become saturated, their composition weakens over time and they deteriorate. This principle applies to every type of absorption material, including shielding devices that claim to absorb radiation. As they absorb the cell phone radiation they become saturated, the head then absorbs the radiation and the cell phone raises its RF outputpower. Even a small amount of radiation can cause ill health. Therefore even with a shielding device that claims up to 99% protection there is still a percentage of toxic radiation entering your body. There are shielding devices that have been independently tested with conflicting results. One such device the manufacturers claim 90% protection, while an independent source arrives at 44% protection.