Note: Receiver Mode: With Microphone Handsfree Calling!!!Transmitter Mode don't Support Mic) Why 4 IN 1 ? 1.Receiver Mode: With Microphone Handsfree Calling.2.Transmitter Mode (TX): Wirelely transfer audio from your non-Bluetooth TV, home stereo system, or CD player to your Bluetooth headphones or speakers.3.USB Transmitter Mode(TX): Wirelely transfer audio from the PC, notebook to Bluetooth headset or speaker through USB port, no audio cable is required.4.Receiver Mode (RX):Wirelely transfer audio from your Bluetooth-enabled phone, tablet, or computer toyour wired stereo, speakers, or headphones. Features: 1.This extremely portable, lightweight wirele audio transmitter & receiver is an ideal wirele audio solution for a wide range of situations and uses2.Transmitter mode:wirelely streams audio from your non-Bluetooth TV, home stereo system, or CD player to your Bluetooth headphones or speakers3.Receiver mode: wirelely streams audio from your Bluetooth-enabled phone, tablet, or computer to your wired stereo, speakers, or headphones4.Switch between transmitter and receiver modes with the simple flick of a switch. Effortlely connect using advanced Bluetooth technology and 3.5mm audio cable (included).5.Broad Compatibility: With the included 3.5mm cable this Receiver Transmitter adapter can widely be used on your car,computer, laptop, home stereo system, headphone, smartphone, Mp3 player, CD player, etc.6.Operation Range: Up to 15m (without any blocking objects)Package Content:1x Bluetooth 5.0 Audio Transmitter/Receiver Adapter1x 3.5mm Aux Cable1x User Manual