Uniden’s R3 is a top of the line Radar Detector with a built-in GPS feature With the R3 you can mark geographical points where you commonly encounter radar transmissions These can be school zones red-light cameras and places where police frequently monitor traffic You can mark these points so the detector will announce “User mark ahead” when you approach them Among other announcements the Voice Notification feature lets you know when you are approaching a radar and what type of radar it is (red light speed etc) Ka Frequency Voice Alert.