Specifications Model: KN321 Technologies: BT5.0, A2DP, AVRCP (receiver mode only) Operation Range: Up to 10m / 33ft (without any blocking objects) Pairing name:KN321 Charging Time: 2 hours Battery Type: Li-Polymer (200mAh) Dimensions: 44 × 44 × 12mm Weight: 18g Package Content 1 x Bluetooth 5.0 Audio Transmitter/Receiver Adapter 1 x Micro USB Power Cable 1 x RCA Cable 1 x 3.5mm Aux Cable 1 xMultilingual instruction manual 1.This extremely portable, lightweight wireless audio transmitter & receiver is an ideal wireless audio solution for a wide range of situations and uses 2.Transmitter mode：wirelessly streams audio from your non-Bluetooth TV, home stereo system, or CD player to your Bluetooth headphones or speakers 3.Receiver mode：wirelessly streams audio from your Bluetooth-enabled phone, tablet, or computer to your wired stereo, speakers, or headphones 4.Switch between transmitter and receiver modes with the simple flick of a switch. Effortlessly connect using advanced Bluetooth technology and 3.5mm audio cable (included). 5.Super-Portable Audio-Streaming Power The KN321 is just 44mm (1.73") across and weighs only 18g (0.63oz), but has got 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.Broad Compatibility: With the included 3.5mm cable and 3.5mm to 2RCA cable, this Receiver Transmitter adapter can widely be used on your computer, laptop, home stereo system, headphone, smartphone, Mp3 player, CD player, etc. and thered light flashes once every three seconds after the pairing is successful. How to use: 1) Plug one end of the audio cable into the audio output of thedevicesand the other end into the audio of the KN321. Confirm that it is in TX mode (red light flash). The KN321 will automatically search for Bluetooth headset or Bluetooth speaker pairing.