Poly Savi 8210 UC Microsoft Teams Certified DECT 1920 1930 MHz USB A Headset Mono Wireless BluetoothDECT 590.6 ft 20 Hz 20 kHz On ear Over the head Monaural Ear cup Omni
1930s Headphones - Etsy
Savi 8410 Office Monaural Microsoft Teams Certified DECT 1920-1930 MHz Headset
Image of Radio and headphones, c 1930
Now hear this: the history of headphones | Music industry | The Guardian