When pairing on the plane, it is recommended that you turn off nearby Bluetooth devices, such as mobile phones. Due to the nature of Bluetooth communication, the delay time varies depending on the processing speed of the device connected to the other side. the Bluetooth transmitter with rechargeable batteries, can last for 12 hours playtime on single charge. Working voltage DC 3.0-4.2V / Working current ≤24mA （About 2 hours, it can be fully charged） The Bluetooth audio transmitter have 2 Aux 3.5mm pins. It is the foldable pin,for some airplanes, you can fold it when you don't need it. 1. Turn on the power. Press and hold the multi-function button for 2 seconds to power on the device and the blue light will turn on for 1 second. 2. Power off: Press and hold the multi-function button for 5 seconds, the red light will turn on for 1 second and the device will power off. 3. Pairing connection. In the power on state, long press the multi-function button for 5 seconds, the transmitter will enter pairing mode, the red and blue lights will flash alternately. 4. Back Connection: After power on, it will automatically enter back connection + pairing mode. 5. Connection interrupted: When the connection range is exceeded or the connection is interrupted, the transmitter will automatically enter the back connection state, and the device will automatically shut down if not connected within 5 minutes 6. Play/Mute Music play mode, short press multi-function key to play or mute music. You can also play/mute by pressing the play/pause button on the receiving device. 7. Clear the Bluetooth pairing list: Clear connection record: With the power off, press and hold the multi-function button for about 8 seconds, the red and blue lights will light up for 1 second and enter pairing mode. 8. Low battery alarm: When the battery is lower than 3.3V, the bluetooth device will automatically alarm and the red light will flash 4 times every 2 minutes; if the battery is lower than 3.0V, the device will automatically shut down. SBC: It is a standard codec. The sound quality has changed. There is a delay (170-270ms during SBC connection) AptX Adaptive: Almost CD sound quality. Low latency (60-80ms when connected in aptX Adaptive) AptX Low Latency: Almost CD sound quality. Delay to limit (40-50ms when connecting aptX LL) AptX HD: Equivalent to high-definition high sound quality (80-100ms when connected with aptX HD)