The GO BT Launcher is used at the origin or the destination location to input the units sensor ranges. These sensors ranges are used to display Upper and Lower temperature parameters on the temperature graph but will not trigger any alert conditions. If the temperature range is not set at the origin location then the receiver can input the Upper and Lower temperature parameters. Please contact our 24/7 Technical Support team if you have any questions about the GO BT Launcher Mobile APP at 1(877) 998-7299 or [email protected].