Feature: 1. The included 3.5mm cable can be widely used in your computer, laptop, home stereo system, earphone, smart phone, MP3 player, CD player, etc. 2. Transmitter mode, wirelessly transmit audio from a computer, non‑Bluetooth TV, home stereo system or CD player to a Bluetooth headset or speaker (via USB interface, no audio cable required). 3. Receiver mode, wirelessly transmits audio from a Bluetooth‑enabled phone, tablet, or computer to a wired stereo, speaker, or headset. 4. In RX mode, find ZF‑169Plus in the Bluetooth settings of the phone to be paired, blue light flashes during the process and stop after the pairing is done, use a 3.5mm audio cable to connect the product to the audio device. 5. TX mode on the PC, driver‑free, plug the USB into the computer interface, and automatically search for other Bluetooth receiving devices, red light flashes when pairing,stops flashing after completion. 6. The transmit mode is used for OS X system, after connecting, you need to select ZF‑169PLUS or USB audio in the system settings‑audio‑audio output device, and you don't need to plug in the 3.5mm audio cable 7. Use the TX/RX switch to change the mode, and the Bluetooth device connected in the transmit mode does not support the call function, small and portable, simple to operate. Specification: Item Type: Bluetooth Audio Transmitter ReceiverMaterial: ABSColor: BlackProduct Length: Approx. 39mm/1.5inProduct Width: Approx. 25mm/1.0inProduct Height: Approx. 12mm/0.5inWeight: Approx. 60.0g/2.1ozTechnology: BT5.0, A2DP, AVRCP (Receiver Mode Only) Working Range: 10m/32.8in(Without Obstacles) Pairing Name (Receiving Mode): ZF-169Plus Transmitter Mode: Red LED Light Receiver Mode: Blue LED Light. Package List: 2 x Bluetooth Audio Transmitter Receiver4 x 3.5mm Cable2 x Manual Note: 1. Use the TX transmission mode on the PC. If a 3.5mm audio cable is connected to the TX audio interface, it will automatically switch to the 3.5mm audio interface and the USB sound card function will be suspended. If you need to use the USB sound card mode, please unplug the 3.5mm audio cable and select ZF‑169PLUS as the sound (speaker) in the lower right corner of the computer. Or in the control panel‑sound, select ZF‑169PLUS under the play bar and set it as the default value.2. Use the USB audio transmitter function on the PC. You cannot adjust the PC system volume to change the sound level. It can only be adjusted in the software (such as audio and video players, etc.), or adjust the volume of the receiving end playback device to change the sound level.