Bluetooth Audio Adapter* 2-In-1 Bridges Your Bluetooth Device To Your Speakers Or Your Bluetooth Speakers To Your Audio Device* Simple one-button switch to shift between transmitter(TX) and receiver(RX) mode. TX Mode:Plug In To Your Non-Bluetooth Device And Pair Up Your Bluetooth Speaker Or Headset. RX Mode: Plug Into Your Non-Bluetooth Speaker And Pair Up Your Bluetooth Phone Or MP3 Player* Bluetooth-enable all 3.5mm media devices (enable Bluetooth receiving: speakers， headphones and more; enable Bluetooth transmission for: MP3， CD / DVD players， e-readers， TVs and more)* Built in battery for portable use， or connect to a USB power source for always-on application.* Ideal For Any Powered Speakers Or Devices Using Standard RCA Or 3.5mm Jack Or AD2P Bluetooth.Feature: With a simple 3.5mm audio connection， give your media players (MP3， CD / DVD players， car audio systems， TVs)， and e-readers Bluetooth connectivity. Stream music from the music players， and audiobooks from your Kindle Fire， to your Bluetooth-enabled speaker - all in a convenient， wireless way. Specification: Bluetooth specification: V3.0 Bluetooth profiles: A2DP and AVRCP Operating distance: Up to 30 feets (10m )Working time: TX Mode: Up to 8 hours RX Mode: Up to 6 hours Charging time: About 2 hours Dimensions: 51 x 27 x 11mm Weight: 11.6g Package inlcude: 1 x 2-In-1 Bluetooth Receiver & Transmitter. 1 x Micro USB charger cable 1 x 3.5mm Audio cable 1 x User Manual