The ES04 has 2 Modes:
Transmit (TX) Mode – For playing audio from an external source to your headphones / earbuds.
RX (Receive) Mode – To play audio from your phone to an external device.
OPERATING INSTRUCTIONS
TX (Transmit) Mode:
1. Slide the mode switch to TX mode.
2. Connect the transmitter to an audio source device that has 3.5mm audio connector output.
3. Long press the power button to turn on the transmitter. The LED indicator will flash red, indicating it is in pairing mode. Follow the manufacturer's instructions for pairing your Earbuds or speakers and the ES04 should connect automatically.
4. When successfully paired, the LED indicator will turn solid red. If you disconnect your earbuds to charge them, when you turn them back on just power cycle the ES04 and it will automatically re-pair with your earbuds/speaker.
RX (Receive) Mode:
1. Slide the mode switch to RX mode.
2. Connect the transmitter to a audio source that has 3.5mm audio connector input.
3. Long press the power button to turn on the transmitter. The LED indicator will flash blue.
4. Using your mobile device, search for Wireless devices and select Wireless ID 'ES04'. It will pair automatically. The LED indicator on the transmitter will turn solid blue once paired successfully.
To use with AirPods:
On ES04 slide the slider switch to TX.
Hold the power button down on the ES04 down until the LED light blinks red.
To enter Pairing Mode on AirPods, first place AirPods inside the charging case. With lid open, press and hold the button on the back of the charging case until the light flashes white. Charging case will turn green and the light on ES04 will be solid red when paired successfully.