Smof Bluetooth CSR 4.0 APTX Transmitter and Receiver 2-in-1 Adapter[Transmit Music to 2 Receivers Simultaneously]With 3.5mm Stereo Output for Speakers Headphone TV Home Stereo(High Audio Quality) In the Transmitter mode,it can connect two Bluetooth receivers at the same time and the music from the two receivers will be no lag One Product with Two Functions:Simple one-button switch to shift between transmitter(T) and receiver(R) mode;300mA Li Battery,work time will be up to 18 hours;Effective Bluetooth distance is up to 30 feet Receiver(R) Mode:Turn any speakers, headphones, stereo system to Bluetooth enabled;Help to listen to music wireless.No worrying about the messy lines Supported profiles: A2DP and AVRCP;SBC, MP3 and AAC.AptX is a digital audio compression algorithm based on sub band ADPCM.The products that support APTX will have low-latency,low BER,low loss,help you enjoy High Quality Audio. Transmitter(T) Mode:For your TV, PC, MP3 Player, DVD Player to enjoy wireless music and sounds.Transmit music/sound to your Receivers with Bluetooth function,like BT speakers or BT headphones,etc