ONE 30 LITER Faraday back pack. WHEN YOU NEED TO PROTECT YOUR DEVICES FROM DIGITAL SNOOPING, ELECTROMAGNETIC PULSES (EMPs) OR WATER. BLOCKS CELLULAR, WIFI, BLUETOOTH, GPS, SAT NAV, KEY FOB, EMF, RFID/NFC, WATER, SOLAR. DROP YOUR DEVICES INTO THIS BAG TO AVOID BEING DIGITALLY TRACKED.