JTS R-4 Instruction Manual page 43

Indicator
Green: power is sufficient, > 2V
Green flashing: microphone mute
Red: power low, ≤ 2V
Red and green flashing alternately: microphone mute
Blue: on for 3 seconds, indicats pairing successfully
Blue flashing: data receiving error
Others
Battery charging is supported. The transmitter turns off automatically when
charging.
When battery is < 1.8V, the transmitter will turn off automatically.
If the microphone is turned off with the mute switch on mute, just slide the
switch up to turn the microphone on.
39
and power low
LED