Maverick ET-77 Instruction Manual page 6

See below examples of what the LCD will look like:
Pre-Alert
When the probe temperature is within 10°F (5°C) of your selected doneness/temperature, the unit will beep twice.
Alert
When the probe temperature reaches your selected doneness/temperature, the unit will beep 3 times per second
for 5 seconds and then silent for 5 seconds. This beeping pattern will repeat and last for 10 minutes.
Note: To stop the alert beep, press the [START/STOP] button.
Manual temperature setting
You can use [HR/?] and [MIN/?] buttons to enter a manual temperature other than the above pre-programmed
temperature.
Timer mode (Count up /Count down)
Count up Count down