Garmin G300 Pilot's Manual page 231

SPEED ALERTS
If the airspeed limitations have been reached, the following messages are
displayed over the pitch ladder. The annunciation is removed once the condition
is resolved.
Alert
Overspeed
Protection
Underspeed
Protection
190-00921-00 Rev. D
Annunciation
External autopilot unit will raise the nose to
max SPeed
limit the aircraft's speed.
External autopilot unit will lower the nose to
min SPeed
prevent the aircraft's speed from decreasing.
Speed Alerts
Garmin G300 Pilot's Guide
annunciations & alerts
Description
213