Talking about Faraday cages, I have anecdotal evidence (i.e. me trying it out) that you can’t get a GPS lock inside your car if it is equipped with V-Cool window tints. I wonder why. I didn’t know that tinted glass products could block out radio waves.
GPS operates at 1575.42 MHz (190mm). My cellphone service operator, Celcom operates GSM at 900 MHz (300mm) and 1800 MHz (150mm). As the wavelengths are similar, it seems that you would block out telephone reception as well (i.e. a conductive mesh that blocks 190mm electromagnetic waves would block 300mm as well). But v-cool doesn’t, as far as I can tell, or maybe it blocks GSM 900 but not GSM 1800?