The effectiveness of interwoven silver has always been controversial. Here is a more recent article on the effectiveness of the Heiq and Livinguard masks https://www.aargauerzeitung.ch/leben/stoffmasken-achtung-fitnessmasken-antivirale-beschichtungen-machen-falsche-versprechen-ld.2125519 To be honest, I am not much wiser after reading this article.