Haavitek Mini Bluetooth 4.1 Receiver with 3.5mm AUX Adapter Hands-Free Car Stereo Audio Adapter Wireless Car Kit How to use: Power on : Long press the Multifunction Button about 2 seconds, it will power on automatically, blue light will flash quickly. Power off : Long press the Multifunction Button about 3 seconds, red light will flash quickly then power off automatically. Instruction: 1.Connect the device to your headphone/Home speakers or Car Stereo System with 3.5mm audio cable. 2.Pair the receiver to your phone 3.Now you can enjoy your music through your Headphone, speakers, Home Stereo System, Car Stereo System or answer calls with hands free. Pair to your phone: 1. Before using receiver for the first time, you must pair it with your phone. 2. When power on it, long press the Multifunction Button for about 3s till red and blue light flash alternately, it will enter into pairing state. 3. Open the Bluetooth function of your phone. 4. Search for the Bluetooth devices LinK-BT4849" and connect to it. 5. Enter the code "0000" if needed 6. If pairing successfully, the indicator light will spasmodically blinking.