Bluetooth Transmitters features: Bluetooth Receiver, Wireless Bluetooth 4.1 Car Adapter & Bluetooth Car Aux Adapter Color: we send based on the color or size of the main image of the product page. Quantity：we send based on quantity on title, if there is no quantity in the title, we send based on description. Instructions: Connected."Power On". "Turn on"."Search for"."Pairing". "Successed 1. Connect the receiver to your non-Bluetooth headphone/Computer Speakers or Car Stereo System. 2. Power on the bluetooth receiver by press it about 3 seconds until the blue and red indicator lights start flashing alternately. 3. Turn on the Bluetooth Function of your phone or music devices that with Built-in Bluetooth. 4. Search for Bluetooth device and select [Bluetooth Music]. 5. Pairing succeseed and start to enjoy the music, just enter the power ON/OFF key calling Hands-Free. 6. Please charge it to make sure it has enough power, already turn on the bluetooth of your devices which is not connecting with other devices. Features : Colour: Black Bluetooth version: 4.1 + EDR Receiving distance: 33FT Frequency response range: 20Hz-20KHz Talk time: 6~8 hours Charging time: about 50 minutes Output power: 30mW Output 3.5mm audio jack Works on car AUX Audio system This Bluetooth Audio Receiver can change your car/home speaker to Bluetooth ones, so you can enjoy pure, clear, wireless music and answer the call in hand-free mode, making your driving safer and more convenient. Can be used 2 devices simultaneously Such as can be connected your home stereo system and smartphone at the same time, streaming music from any of them, up to 33ft connection range assure low signal delay. Application for the phone stereo system Those Bluetooth adapters make you listen to music with ease and freedom, never miss any phone call while you are enjoying the music. Up to 7 Hours Battery Life The built-in 1 mAh lithium battery with large capacity With protection board provides, up to 7 Hours of nonstop music streaming, or 6~8 Hours phone call and only needs 50 minutes full charge