A Key Fob Guard Faraday bag is a must-have accessory if your car utilizes a remote key system. It is a privacy and security case for your key fob or keyless entry fob - a single sleeve that blocks the wireless connection from your key fob to your car, keeping you and your car safe. Smart keys are vulnerable to hacking and give electronic thieves access to remotely open and potentially steal your car. Protect your valuables at home, on the road, and on the town.