This box in the display shows the active and standby radio
frequencies for the NAV (VLOC)
radio. Dial the frequency with the concentric knobs at the bottom left and switch the
standby and active frequencies using the "V" flip-flop button on the left.
To prevent confusion with the "NAV" chapter, Garmin refers
to the NAV radio as the "VLOC"
radio. VLOC stands for VOR/Localizer.