Our design uses two layers of GoDark RF-shielding fabric to ensure the best protection. The inner felt liner allows for privacy without compromising your safety. The liner ensures the metallic blocking material cannot inadvertently activate your cell phone, including gestures when the screen is off, allowing you to keep your device powered on while in the Faraday bag.The inner felt liner protects the shielding material from damage and prolongs the lifetime of the bag.We know that these bags must never fail, so we designed our bags with roll-top closures and sturdy straps. GoDark bags are also made with a very durable 600D Poly Outer Shell with a PU face coat and a TPU backing that is both water and puncture resistant. A thin inner padding and felt liner further secure the signal-blocking material from being damaged with repeated use. Finally, our Faraday products undergo rigorous third-party lab tests to confirm proper signal blocking.