a real faraday cage and a fake one

There's no shortage of crazies and conspiracy theorists in the world, and some companies are cashing in on the madness.   5G conspiracy theorists believe a wide array of stuff from 5G causing cancer to 5G spreading COVID-19.  Recently some companies started selling fake "Faraday Cages" to these not-so-tech-friendly people.  

The only problem with these devices is that they do what they are supposed to... block signals from your router which tends to be a problem if you're looking to use your wifi or the internet.

crazy guy with tin foil hat on him and his cat
These overpriced devices are basically just metal cages that block about 90% of the signals going to and from the router.  Congratulations, your 1GB internet is now 100mbs, you did it!

A true Faraday cage would block 100% of signals rendering your router and wifi completely useless which actually might not be such a bad thing for some of these conspiracy-susceptible folks.

Pretty much every single one of your wireless devices from your Fitbit to your AirPods,  send and receive packets of data, broadcasted through some form of electromagnetic radiation.

the spectrum of radiation and electromagnetics
This type of radiation is considered non-ionizing radiation, is less energy-dense and less-harmful than ionizing radiation like that which comes from the sun's ultraviolet rays. Ionizing radiation can cause diseases like skin cancer and other health issues. Non-ionizing radiation can't change your DNA, so it can't cause cancer.

"5G operates at a higher frequency than other communication standards we're used to, like 3G, 4G, or LTE. Those networks work at frequencies between about 1 to 6 gigahertz, while experts say 5G sits closer to the band between 24 and 90 gigahertz, still safely within that non-ionizing band of radiation." - PopularMechanics

So put away your tinfoil hats (or don't) but the only thing you're accomplishing by covering up your router is slower internet speeds and longer wait times.