1. Once Fully , You Can Listen For 14 Hours. Built-In 250mAh Lithium Battery, Which Can Be Used Wirelessly When Fully . It Can Be Used While Charging When The Battery Is Low. 2. The Eye-Protecting Light Ring Refuses Blind Insertion. The Working Status Is Clear At A Glance. It Is Eye-Catching And Not Dazzling. It Is More Convenient To Use At Night. 3. Install The Bluetooth Function On The Tv And Connect The Bluetooth Headset 4. Turn Wired Into Wireless, A New Music Experience, Connect Old Speakers, And Easily Transform Into Bluetooth Speakers 5. High-Definition Music, Listen To Music All The Way, Hands-Free Calls, Free Your Hands, Car Audio, Turn Into Bluetooth Audio In Seconds, Listen To Mobile Music All The Way 1.Model: ET-BR04 2.Bt Version:5.3 3. Output Interface: 3.5mm Stereo Interface 4. Frequency Response: 50~200HZ 5.Battery Capacity: 250mAh 6. Transmission Distance: 10-15m 7. Charging Port: USB-C Note: Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Not Affect The Use Colour:As Shown Material:ABS Package Contents: 1 x AUX Car Bluetooth Receiver 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.