1. This extremely portable, lightweight wireless audio transmitter and receiver is an perfect wireless audio solution for a wide range of situations and uses2. Transmitter mode: wirelessly streams audio from your non-Bluetooth TV, stereo, or CD player to your Bluetooth headphones or speakers3. Receiver mode: wirelessly streams audio from your Bluetooth-enabled phone, tablet, or computer to your wired stereo, speakers or headphones4. Switch between transmitter and receiver modes with the simple tap of a switch. Closes effortlessly using advanced Bluetooth technology and 3.5mm audio cable (included).5. Super-Portable Audio Streaming Power:The KN319 is just 44mm (1.73 inch) across and weighs only 18g (0.63 oz), but has powerful wireless audio streaming capabilities. Slip this transmitter & receiver into your backpack or laptop bag and take it on-the-go without the slightest effort .6. Wide Compatibility: With the included 3.5mm cable and 3.5mm to 2RCA cable, this Receiver Transmitter adapter can be widely used on your computer, laptop, stereo, headphones, smartphone, Mp3 player, CD player, etc .SpecificationsModel: KN319Technologies: BT4.2, A2DP, AVRCP (receiver mode)Operation Range: up to 10 m / 33ft (without blocking objects)Charging time: 2 hoursContinuous Use Time: 6 hours (Receiver Mode) / 5 hours (Transmitter Mode)Battery Type: Li-Polymer (200 mAh)Weight: 18gColour:blackMaterial:ABSDimensions: 44 x 44 x 12mmPackage Contents:1x Bluetooth 4.2 Audio Transmitter/Receiver Adapter1x Mini USB Power Cable1x RCA Cable1x 3.5mm Aux Cable1x User ManualOnly the above package content, other products are not included.Note: Light 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.