Wireless Key Finder - With the GPS remote control with wireless 4.0 system, you can easily search/locate lost items. The item locator app supports iOS and Android phones. You can download the iSearching app from the Apple Store or Google Play. (Note: iOS 8.0 or above / Android 4.3 or above) Two-way search - When you want to find the target object, just click the reminder in the app and the tracker will send an alarm to remind you of the object's location. When searching for your phone, simply press the tracker button twice in quick succession and your phone will sound an alarm, whether your phone is muted or not. Intelligent Disconnect Reminder - If the cell phone and wireless tracker are not within the effective range, the cell phone and tracker will remind you. The APP records the location where the item was last disconnected from the mobile phone to refine the search area. This is a great gift for those who forget things. Effective coverage - The effective distance between the cell phone and the GPS button viewfinder is about 15-30 meters indoors and about 25-50 meters outdoors. In case of obstacles, the effective distance is the shortest distance Small and portable - The finder is very small and lightweight, you can put it in your wallet, hang it on your backpack, suitcase and keys. Easy to carry. There are 4 trackers in our package which can meet your additional needs.