Supposedly, your cellphone still sends out information to the service provider about your activities even after you’ve turned it off. If you want to make sure that no one can track those signals, you need a case or bag from MIAmobi. The lining in these bags contains colloidal silver, which blocks all radio frequencies to/from your phone. You’ll be completely off the grid, so no one can track your whereabouts. That does mean you’ll also be unable to receive phone calls while the phone is in the bag, but that can be a plus, especially for teenaged drivers, to prevent the temptation to text or make calls while driving. Another benefit of colloidal silver is that it is antimicrobial. Cellphones carry a lot of germs, and placing one in these bags is said to sanitize the phone.
MIAmobi bags come in various sizes to fit most cellphones, smartphones, and even tablets. No prices are shown on the website, but they do have an email address you can use to request purchasing information.