Latest Bluetooth 5.4 Technology: With Bluetooth 5.4, connect the device faster and get a more stable signal transmission. Whether watching videos or playing games, the synchronization of audio and video is significantly improved, reducing the trouble caused by delay and improving the entertainment experience. | Maximum 18 Hours Battery: It can last up to 18 hours to meet your all-day use needs. This device is the best companion whether you frequently travel for leisure or business trips. You can enjoy uninterrupted music or calls without frequent charging.(RX: 18H/ TX: 16H ) | Built-in Microphone: The built-in microphone of the ugreen allows you to answer calls directly without interrupting music playback when the device is connected to a mobile phone to play music; ugreen ensures that you do not miss any important calls while enjoying music. | 10M Transmission Distance: The 10-meter transmission distance allows you to move freely within your home or office without worrying about interruptions in the audio signal. No matter where you are in the room, you can enjoy stable audio transmission. | 2 In 1 Bluetooth Transmitter Receiver: In TX mode, you can connect the device to a TV, airplane, and other devices without Bluetooth function, and then connect Bluetooth headphones to listen to music; in RX mode, you can turn non-Bluetooth stereo devices such as car audio, old speakers into Bluetooth devices, and then connect mobile phones, computers, etc. to play music; without the constraints of cables, move more freely without affecting audio playback.