The latest Bluetooth 4.1 technology with A2DP and AVRCP Bluetooth protocol for enhanced audio quality , Strong Compatibility,Low Latency and faster pairing, intelligent compatible, Android, IOS system mobile phones and PAD, and all Bluetooth audio equipment. (Note) If your Bluetooth version is lower than version 2.1 or 3.0, it will cause signal transmission delay. Transmitter Mode: Connect the audio devices(such as MP3, MP4, TV and PC, etc.)via the audio cable or RCA. Bluetooth transmitter function wirelessly streams audio to Bluetooth speakers or headphones from your TV or older media devices like portable CD players that lack built-in Bluetooth. Receiver Mode: Turn the traditional car or home stereo, speaker or car stereo into Bluetooth-enabled ones. Pair by Bluetooth-enabled audio sources such as smartphone, tablet or laptop to enjoy music wirelessly. NOTE: The adapter needs to be set in the transmit mode (the audio cable should be plugged into the product's red earphone jack). During the charging process, current may interfere with the adapter and may generate noise. It is recommended to use it after full charge. Lightweight and portable Bluetooth Transmitter & Receiver (Easy to install and simple to operate) is an Perfect wireless audio solution for a wide range of use cases: Bluetooth Devices A2DP profile for Windows Phone, smartphone, Android, Apple, iPhone 6, iPhone 6 Plus, Samsung Galaxy Note 4, Galaxy S5, Kindle, Kindle Fire, iPad, Nexus, Google, Tablets, Laptop, PC, & Stereo System with 3.5mm port This Bluetooth Audio Transmitter & Receiver 2-in-1 Broadcast audio output from your TV or old portable CD player to wireless speakers on the other side of the room without cumbersome cable management. Use the wireless receiver function to upgrade your audiophile home stereo system and wirelessly stream music from your phone or tablet. Function Operation: ON: press the button the blue light will blink. OFF: press the button 5