https://www.amazon.com/Faraday-Defense-Superior-Shielding-Performance/dp/B08N2WBWWQ/ref=sr_1_14?dchild=1&keywords=wifi+router+guard&qid=1607317827&sr=8-14
This one has 4+ review ratings.
https://www.amazon.com/Upgraded-Blocking-Faraday-Technology-Universal/dp/B0814BYHV6/ref=sr_1_4?dchild=1&keywords=wifi+router+guard&qid=1607317992&sr=8-4