Here is a military grade faraday bag that can block WiFi, Bluetooth, 4G, GPS, RFID, and radio signals to protect your devices against wireless hacking, solar flares, and EMPs. The Goal Zero Yeti Faraday Bag has a water resistant ballistic nylon exterior and two layers of shielding fabric.
This faraday bag meets the MIL-STD 188-125 standard. It can be used to protect your emergency generators and other sensitive devices. You can find out more about it here.