Claims about action range of radio charms are relative.
You often ask us – What is the range (in meters) of radio charms of your system in my office?
The question is about the same as if you asked a car salesman:
What speed can be reached by this car?
What would he say?
How do you think?
Most likely, he would have said something like this: "It gets 220km /h on the free highway under ideal weather conditions, road surface, and your well-being"
And the city? - You would ask again.
He'd probably just shrug, and not because he is an ignoramus - but because external factors affecting the speed in the city are too strong.
The question about the range of the radio charms in urban / office environment is similar.
Yes, the manufacturer promises 100 meters range of radio charms, but what does that mean?
The answer is simple - it's guaranteed communication range under ideal conditions, i.e. when there is no radio interference and shielding structures, - in other words - in the open field.
And because required parameters in a modern office environment are far from ideal – we mean the presence of partitions, walls, furniture and other screening structures and radio magnetic fields interfering in almost the entire range of radio frequencies - the range of the radio transmitters is greatly reduced.
That’s not the deal about radio charms - their schemes are approximately the same type, and not the deal about radio charm manufacturer - we have tried radio charms of 5-6 producers. The decrease in range of the radio systems in modern office is reality to be reckoned with.