Don't bother. I backed this on indiegogo, and apart from the traditional delays (it is only now for sale and it is about six months late) the device is completely useless.
It has a range of about 15 feet in direct sight, less if anything is in the way
It has a brilliant app, which has a separation alert so if the trackr and the phone with the app part company for any distance the phone sounds an alert and the tracker emits a whistle. The trouble is that the trackr signal drops out all the time so they both keep sending alarms, and it works even when the phone is on silent, and both things are in your pocket. I have had it two days and am sick of it.