Feature:[Wireless Key Finder] Using the GPS remote control with 4.0 wireless system, you can easily search/locate lost items. Item locator with app supports iOS and Android phones. You can download iSearching app from Apple Store or Google Play. (Note: iOS 8.0 and above / Android 4.3 and above)[Two-way search] When you want to find a target object, just click the reminder in the app and the tracker will send an alarm to remind you the location of the object. When you find your phone, just press the track button twice in quick succession and your phone will sound an alarm whether your phone is muted or not.[Smart disconnect reminder] If the cellphone and wireless tracker are not within the effective range, the cellphone and Finder will remind you. The APP saves the location where the item was disconnected from the phone last time to narrow down the search area. It is a great gift for people who forget some things.[Effective Coverage] The effective distance between mobile phone and GPS button sight is about 15-30 meters indoors and 25 to 50 meters outdoors. When encountering obstacles, the effective distance is the shortest distance[Small and portable] The sight is very small and light. It can be put in wallet, hung on backpack, suitcase and keys. Easy to carry. There are 4 trackers in our package to meet your additional needs.