Features:Wireless remote control electronic key finder, environmental protection and no radiation.Easy to use, all you have to do is whistle and it's alarm will sound.Can be put in bags or other items as a anti-lost device to use, it can also be used as a mobile pendant.Help you easily find keys, wallets, MP3 and etc.Sensing range about 8-10 meters, the louder the whistle, the sensing range is long.Dimensions: 5.3 * 3 * 1cm/2.1 * 1.2 * 0.4inch; Key ring is not included.Specification:Material: ABS Plastic & Electronic ComponentsColor: Green, Blue, Red (optional)Battery: IncludedSensing Range: 8-10 metersSize: 5.3 * 3 * 1cm/2.1 * 1.2 * 0.4inchPackage Weight: approx.20gPackage List:1 * Anti-Lost Alarm Key Finder