Squelch modes allow you to filter out nearby radio users on the same channel as you.

Open

Allows a traditional squelch setting to filter out static. You can increase the squelch level to filter out unwanted noise.

CTCSS

Continuous Tone-Coded Squelch System uses an inaudible low-frequency tone before each transmission to filter out unwanted noise. You hear only others on the same radio channel who are using the same CTCSS tone frequency as you.

DCS

Digital Code Squelch uses digital codes before each transmission to filter out unwanted noise. You hear only others on the same radio channel who are using the same DCS code as you.

The CTCSS and DCS squelch modes decrease your radio range slightly.