This Extremely Portable And Lightweight Wireless Audio Transmitter And Receiver Is An Perfect Wireless Audio Solution For A Variety Of Situations And Uses, The Kn319 Is Only 44mm (1.73 Inches) In Diameter And Weighs Only 18 Grams ( 0.63 Oz), Yet Boasts Powerful Wireless Audio Streaming Capabilities. Throw This Transmitter And Receiver Into Your Backpack Or Laptop Bag And Take It With You Effortlessly. Transmitter Mode: Wirelessly Stream Audio From Your Non-Bluetooth Tv, Home Stereo System, Or Cd Player To Your Bluetooth Headphones Or Speakers Receive Mode: Wirelessly Stream Audio From Your Bluetooth Phone, Tablet, Or Computer To Your Wired Stereo, Speakers, Or Headphones Switch Between Transmitter And Receiver Modes With A Simple Flick Of The Switch. Connect Easily Using Advanced Bluetooth Technology And 3.5mm Audio Cable (Included). Ultra-Portable Audio Streaming Capabilities Wide Compatibility: Comes With 3.5mm Cable And 3.5mm To 2rca Cable, This Receiver Transmitter Adapter Can Be Widely Used On Your Computer, Laptop, Home Stereo System, Headphones, Smartphones, Mp3 Players, Cd Player Etc. 1. Technology: BT4.2, A2DP, AVRCP (Receiving Mode Only) 2. Operating Range: Up To 10m/33 Feet (Without Any Obstruction) 3. Charging Time: 2 Hours 4. Continuous Use Time: 6 Hours (Receiving Mode) / 5 Hours (Transmitting Mode) 5. Battery Type: Lithium Polymer (200mah) 6. Size: About 44x44x12mm 7.Colour:black 8.Material:ABS+plastic Package Contents: 1 x Bluetooth Audio Adapter 1 x Micro-Usb Power Cord 1 x RCA Cable 1 x 3.5mm Auxiliary Cable 1 x English Instruction Manual Note:Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Will Not Affect The Use Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.