Don’t be mislead by a common misconception started in the 90′s that wired headsets, that the headset that came with your cell phone is a safe alternative to placing a phone to your head.   This is simply not true at all! Ordinary headsets use a wire to deliver sound to an electronic earpiece that can deliver electromagnetic radiation into your head directly through your ear canal.
I debated whether to give it 3 or 4 stars: on features, speed of delivery, and quality of construction, it definitely deserves 4 stars. If I can measure and verify the emf reduction, then I will change the rating to 5 stars. Since the whole point of using it is to block excess em radiation, I can't really give it 5 stars without more proof that it really does so.
The peer reviewers did have some quibbles with the study; some wished it could have lasted longer (the rodents were exposed to radiation for two years) to catch later-developing tumors, for example, but others on the panel noted that the longer a rodent lives, the more likely it is to develop tumors regardless of radiation, making it harder to find the signal in the noise. Others wanted the researchers to have dissected the rodent brains more than they did, to seek hard-to-find tumors. But they noted that science is an iterative process; the study wasn’t perfect, but it’s better than anything that’s been done so far.
Let’s be honest, we’re addicted to our smartphones. According to an ABC news report, the average person checks their phone 150 times per day, not to mention the other 15 hours per day it sits in your pocket. It’s also nothing new that cell phones emit Electromagnetic Fields/Radiation (EMF/EMR) when it’s glued to the side of our head more than 22 times per day. 
Jump up ^ "Téléphones mobiles : santé et sécurité" (in French). Le ministère de la santé, de la jeunesse et des sports. 2 January 2008. Retrieved 19 January 2008. Lay article in (in English) making comment at Gitlin, Jonathan M. (3 January 2008). "France: Beware excessive cell phone use?: despite lack of data". Ars Technica. Retrieved 19 January 2008.
Researchers have carried out several types of epidemiologic studies in humans to investigate the possibility of a relationship between cell phone use and the risk of malignant (cancerous) brain tumors, such as gliomas, as well as benign (noncancerous) tumors, such as acoustic neuroma (tumors in the cells of the nerve responsible for hearing that are also known as vestibular schwannomas), meningiomas (usually benign tumors in the membranes that cover and protect the brain and spinal cord), and parotid gland tumors (tumors in the salivary glands) (3).