Product information: Color: Black Operating range: maximum 10 m (without obstacles) Mating name: KN321 Charging time: 2 hours Interface: USB 3.5mm audio Battery type: lithium polymer (200 mAh) Size: 444412mm Weight: 18g Packing List: 1 x Bluetooth 5.0 Audio Transmitter / Receiver Adapter, 1 x Micro USB Power Cable, 1x RCA Cable, 1x 3.5mm Auxiliary Cable, 1x User Manual Features: 1. This portable lightweight wireless audio transmitter and receiver is an ideal wireless audio solution for various situations and applications 2. Transmitter mode: wirelessly stream audio from a non-Bluetooth TV, stereo or CD player to a Bluetooth headset or speaker 3. Receive Mode: Wirelessly stream audio from Bluetooth-enabled mobile phones, tablets or computers to wired stereos, speakers or headphones 4. Simply press the switch to switch between transmitter and receiver modes. Use advanced Bluetooth technology and 3.5mm audio cable (included) for easy connection. 5. Ultra-portable audio streaming power adapter KN321 is only 44mm (1.73 inch) and weighs only 18 grams (0.63 inch) but has powerful wireless audio streaming function. Slip this transmitter and receiver into your backpack or laptop bag and take it with you with ease. 6. Wide Compatibility: This receiver transmitter adapter is equipped with 3.5mm cable and 3.5mm 2 RCA cable, widely used in computer, laptop, home stereo, earphone, smartphone, MP3 player , CD players, etc.