The smaller leather key cases, which are more suitable for taking with you. In addition, there is also a small ring on the outside, with which you can attach the bag to a bunch of keys Even if you stand right next to the car with the key in the case, the car cannot be opened, so the transfer of information is perfectly blocked These bags work as keyless fob signal blockers, able to block fob's RFID and NFC signals, preventing hackers/thieves from remotely controlling and gaining access to your car or auto. These pouches are safe for everyday use. Equipped with nano-coating, the bags appear with unique carbon fiber texture, soft, wear-resistant, anti-demagnetization and anti-radiation, which ensure long-term protection. The bags are compact enough to store in your purse or backpack for easy carrying. The attached chain with a ring head provides convenience for hanging and improves portability. Size:Carbon Fiber Packaging dimensions : 14 x 9.5 x 1 cm; 45 grams