2.4 to 2.485 GHz
When I was a kid (i'm 71 now) I dreamed of being able to hear what was on above the FM broadcast band. 2,400 Mhz. was unheard of, let alone having a receiver to tune into it. Now we have Bluetooth transmitters and receivers, many the small size of only a few inches. I have a Bluetooth speaker the size of my fist that works with the Amazon Echo Dot, also a Bluetooth transmitter the size of a postage stamp that I plug into my Ham Radio, TV, Stereo, or computer. This with a pair of Bluetooth headphones I can walk about the house.
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