Over Speed Alerts: This setting is for your overall speed. Any time you go faster than this, regardless of speed limit, your detector will alert you to slow down. By default, this is set to 70MPH. Change this to a higher speed or turn it off entirely.
Over Speed Limit Alert: This setting is based on your GPS location and the known speed limit for the road, if any. Speed limit data is dependent upon a live data connection via app Bluetooth or Wifi. Any time you exceed the speed limit of the road by this amount, you will be given an alert to slow down. By default, this is set to Speed Limit, meaning any overage is alerted. You can set this to a higher speed or turn it off entirely.
Cruise Alert: This setting is to reduce incoming radar alerts to a double-beep sound when you're going UNDER this speed. This is useful for when you're driving slow and don't need loud full alerts. By default, this is set to 20 MPH meaning you get full alerts if your vehicle speed is over 20 MPH, but a double-beep alert under this speed. If you do not want full alerts under a certain speed, set this higher. If you always want to be alerted full tilt regardless of your speed, turn this off.