Cell phone jammer is that Faraday device just muffle your phone's ringer. I got this for my cell phone a Samsung Galaxy Note 8. It fits nicely in there. I tried calling the phone. No ring! I connected my phone to a bluetooth speaker and started playing music, then placed my phone inside the bag. Disconnected! I tried texting and email my phone while it was in the bag. They didn't go through! I am not a technical expert, but the device does seem to cut off connectivity with the phone, which is why I purchased the device. Can't beat the price!