Bluetooth version: Bluetooth 5.3 Compatibility: LDAC ,,AAC,, -Adaptive,-LL,-HD,-Adaptive, LHDC Bluetooth chip: QCC5125 chip: Dual ES9039Q2M amp: Dual TI OPA2107+ TPA6120A2 play pause button: Yes Previous/Next key:support volume key:Yes BASS Gain:Supported song before and after adjustment: Yes Transmission distance:13M Volume knobl: support Output power: 3.5/2.5/4.4??400mW+400mW(32??) Earphone ohm support::6-300?? 9039Q2M DNR:130DB SNR:?? 120DB +N: 0.008(32??): Plug type: 3.5mm+4.4mm USB : Type-C 5v 2a charge and support 44.1&48k PC usb Battery capacity:2000mAh Endurance: 3.5??8h Colour:Black Material:Plastic + Metal Package Contents: 1 x Bluetooth Decoding Headphone Amplifier (Due to different product batches, the appearance , which does not affect the use) 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.