Pro with Double Volume and Range, Replace the Battery and not the Cube each year | With Crowd Find Attach CUBE to anything and Let the Cube Community be your Search Party | Lost your Phone? Use your CUBE to locate your phone with ring, vibrate, and flash, even if the app is not running | No need to replace CUBE each year. Just replace battery yourself once a year. Extra battery included | Simple CUBE Tracker app will show last known location on a map, uses bluetooth to tell if you are near or far, press find and CUBE will ring. Also has a separation alarm to alert you if you left something behind.