Fast & Stable Connection: Built-in quality Bluetooth-compatible 5.1 chip, fast response, more stable and faster connection. Bluetooth-compatible signal transmission distance is about 20 meters, allowing you to connect to Bluetooth-compatible without restrictions NFC Function: It has an NFC pairing chip. Once the phone is close to the sensing area, it will automatically connect to Bluetooth. Supports various mobile phones and tablets, eliminating the trouble of manual connection Blue Indicator Light: The signal source indicator is bright but soft, and not dazzling Long Working Time: Built-in 500mAh rechargeable lithium battery, after fully charged, it can support continuous listening to songs for about 10 hours Music Playback: Supports U disk/TF card to play music Infrared Remote Control: It comes with an infrared remote control, supports 5~8 meters connection, can operate mode/signal, adjust volume, switch songs, mix, microphone and other operations on it Built-in Microphone Port: Built-in 6.5mm microphone jack, anti-howling design, supports microphone access for singing Wide Compatibility: Suitable for various audio devices, such as old speakers, computers, HDTVs, etc Easy to Use: No need to download drivers or apps, it is plug-and-play, and no tedious steps are required Specification: Bluetooth-compatible version: 5.1 Supported protocols: A2DP, AVRC Working frequency band: 2.402GHz -2.480GHz Power level: Class II Sensitivity: -85dBm<0.1%BER Signal-to-noise ratio: ≥90dB Distortion: ≤0.1% Interface type: Input: BT+USB+TF interface Output: 3.5mm AUX+RCA Supported formats: MP3/WAV/WMA/APE/FLAC/G729/M4A/ALAC/AMR/DTS/MIDI/G726/MTY Screen size: 36*8mm Working current: <40mA Battery capacity: 3.7V/500mAh Charging current: about 500mA Charging time: about 1.5h Listening time: about 10h Bluetooth-compatible distance: ≤20m (open space) Charging method: Micro USB 5V/0.5A Compatible devices: Android, iOS phones and for iPad, active speakers, amplifiers and other playback devices