Defective item: Marks from crimping on the metal fittings. Contents and surface are not affected. Product: Relay Attack Prevention Key Case (boxed) Material: High-quality PU leather Size: External 10x5x3.5cm, Internal 8cm long x 4cm wide x 2cm deep (Please note that there may be slight variations.) Color: Gray Car Key Capacity: 1 Weight: 160g Compatible Vehicles: Compatible with all types of domestic and foreign cars, including Toyota, Honda, Nissan, Mazda, Suzuki, Subaru, BMW, Benz, etc. [Relay Attack Prevention] Simply place your smart key inside the radio wave blocking case to completely block the key's radio waves. Effectively prevents car theft via smart key radio wave relay. The best countermeasure against relay attacks. [Radio Wave Blocking] The back layer radio wave blocking fabric is doubled to enhance the radio wave blocking effect and product durability. [Product Function Test] After receiving the product, put your smart key in this case and try to operate the car door ON/OFF. If it doesn't work, it proves that the smart key signal is not leaking. [Note] Radio waves cannot be blocked unless the lid is completely closed.