The item is a Transmitter Receiver. As a Audio Transmitter, it can be connected to the audio devices without function via the included 3.5mm Audio Plug, changing these audio devices into -enabled audio devices, and making it work with -enabled Headset and Speaker. Features - Receiver Mode: Change the traditional Car Stereo system or Home Audio System into -enabled ones. After paired, play music wirelessly from your -enabled Smart Phones, Laptop, Tablet and more. - Transmitter Mode: It can be connected to the audio devices (such as MP3, MP4, TV and PC, etc.) without function, changing them into BT-enabled ones, and making it work with BT-enabled headset and speaker. - Low Power Consumption: Built-in 60mAh Li-polymer Battery ensures up to 4 hours working time, you can enjoy wireless free all day long. Easy connection, without any driving and downloading APP. - Fast Connection: Built-in enhanced signal transmission circuit, the connection is fast and stable. Automatic memory connection function, the operation is simpler and the connection is more convenient. Specifications - Color: Black. - Material: ABS. - Size: 7.5 x 2 x 2 cm. - : V5.0. - Protocol Supported: HFP/HSP/A2DP/AVRCP. - Transmission Distance: 10M (open space). - Working Time: about 4 hours (depend on audio volume). - Charging Time: about 2 hours. - Temperature: -10~70. - Interface: 3.5mm.