To change the unit of measurement on the Callaway 400s Laser Rangefinder from meters to yards, follow these steps:
Turn on the device by pressing and releasing the power button.
Press and hold the mode button until the unit of measurement on the display starts flashing.
Use the mode button to toggle between meters and yards.
Once you have selected your preferred unit of measurement, press and release the power button to confirm your selection.
The unit of measurement will stop flashing, and the device will be ready to use in your selected unit of measurement.
Note that the selected unit of measurement will be saved and used by the device until you change it again using the same process.