This locator is universal for Android and ISO System. Is there a distance limit? No distance restrictions, globally available, as long as there are any devices within 10-50 meters nearby, the equipment can be fixed in place. Is it real-time? When there are devices nearby, it can achieve the effect of near real-time positioning. Moreover, the more devices there are, the more accurate the positioning be. If there are no devices around, positioning not be possible until devices appear nearby (there be an interval of 5 to 15 minutes for location updates). What is the working principle? The device send out a secure Bluetooth signal every two seconds, allowing nearby devices (mobile for phones, Computer, for , etc.) to receive and upload to as a Service to generate master location data. Only the owner of the locator can retrieve location data. So there are multiple nearby devices, the faster the update, the more accurate it is. Which places are more suitable for use? It is generally more suitable in busy urban areas or places with more people using devices.Remote areas or places with fewer people using devices are not suitable.Please decide whether to purchase based on your own situation. Why is positioning inaccurate? There may be no devices nearby, and it take 5-15 minutes to sort out the location. (Bluetooth locators may not be as accurate as GPS, but GPS requires a SIM card, data card, and charging every few days). Our Bluetooth locator has the advantage of using button batteries, which can year without the need for recharging. (1) No additional expenses are required. (2) A CR1225 button battery can last for about 2-3 months. Colour: Black Material: plastic Package Contents: 1 x Locator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.