Garmin handheld two way radio, compatible list:
Headsets and Microphones
This device is compatible with many headset and microphone accessories that connect using a 2.5 mm jack
By default, the device is set to detect automatically when a new headset or microphone is connected.
NOTE: When connecting a headset with a push to talk (PTT) button, you must press the PTT button after connecting the headset for the device to detect the headset.
This device is compatible with Voice Operated Transmission (VOX) devices. These accessories allow you to use the device hands-free by transmitting automatically when a voice is detected. You can adjust the sensitivity level of connected VOX devices (Advanced Radio Setup).
Advanced Radio Setup
From the radio app, select Menu > Radio Setup > Advanced Setup.
Sets the type of accessory headset or microphone you are using with the device
Sets the sensitivity of a connected Voice Operated Transmission (VOX) accessory. A lower VOX setting is recommended for quiet environments, and a higher VOX setting is recommended for noisy environments.