I am using cabled old-fashioned handset for my android phone to protect my brain from harmful radioactivity fof mobile phone.

The companies are blind to the big reality that all these phones, computers are damned source of harmful radioactivity.
There are ways to avoid harm of radioactivity. If one uses headsets with a cable, then human-tissue ionizing harmful radioactivity from phones will not be close to head. The harm will be 100 times less.

 The bluetooth wireless apparatus is not good for head health, its material should be away from head. The batteries are not healthy on skull. Though putting entire phone radioactivity on head is worse than headset batteries/machines.
Wired headsets might not be comfortable, but they are healtier. They are cheap.
I do not talk on phones that much. I myself do not have any plan to abondon modern phones, computers, etc. but current generation is growing with such terrible radioactivity from phones.
Brain cancers are increasing because of the damages of phone radioactivity on skull.
I wear gloves when I use my tablet phone, but to talk on phone is different, to hear on phone, head/ear should be bare.

My old phone does not have any port to connect to such retro phone handset, fortunately my new android-phone-pad connected and worked well with handset. My voice is send same, but the quality of hearing maybe slightly a little bit less. whatever, I am happy that such a simple cheap($8) accessory will keep harmfull radioactivity away from my valuable brain.