Technical specifications, , Sound scheme 2.0, stereo , Number of bands 1 , Type of earcups bass reflex type , Bass reflex port place back , Total output power (RMS) 20 W , Signal to noise ratio 85 dB , Frequency range 85--20000 Hz , Driver size 2 x 2.5 " , Driver unit impedance 4 Ohm , Wireless connection Bluetooth 5.1 , Operation range 10 m , Backlight LED , Lighting effects yes , Backlight off function yes , Power supply Li-Ion battery, via USB, 5V , Battery capacity 2400 mA·h , Battery type 18650 , Operation time on one battery charge 5 hrs , Battery charging time 6 hrs , Built-in FM-tuner yes , Tuner frequency range 87.5--108 MHz , MicroSD card support yes , USB flash drive support yes , Maximum supported capacity of memory card / USB flash drives 32 GB , Audio file formats MP3 , Microphone jack 6.3 mm jack , Microphone in ports One , Automatic shutdown time 10 min , Housing material plastic , Color black