1. [Works with Find My App] After the key tracker card is paired with the Find My App, you can set a left behind alarm and find nearby lost items with a loud alarm. This key finder has a Bluetooth range of up to 328 feet and a beep of up to 80dB, which is enough for you to easily find it indoors or outdoors! 2. [] The wallet tracker card supports wireless charging, and there is no need to replace the battery. With just one charge, you can enjoy a full year of use, saving the trouble of weekly charging. The key tag has an ultra-long battery life of up to 100 years, ensuring long-lasting and reliable performance. This is an environmentally friendly locator designed for sustainable development. 3. [Privacy and Security] All communications with the Find My Network are anonymous and encrypted. The luggage tracker does not store location data or history, prioritizing your privacy. 4. [Ultra-thin] It weighs only 0.42 ounces and measures 2.12 inches long x 1.77 inches wide x 0.11 inches high. The key tracker is about twice as thick as a credit card. It fits perfectly in wallets, passports, suitcases, etc.