Signal To Noise Ratio:3.5mm:120dB 4.4mm:115dB WIFI:No Bluetooth:No PCM:Yes DSD (Direct Stream Digital):Yes Model:ES9038Q2M Channels:2 (2.0) Package:YES Output Power:3.5MM:280mW/32ohm 4.4MM:1100mW/32ohm Model Number:SK02 Type:Mini Amplifier Recommended Headphone Maximum Impedance:251-300 Ohm Built-in Battery:Yes Output Type:OPTICAL,LINE OUT (AUDIO OUT),Balanced Out Input Type:USB,OPTICAL Name: Audio Certification:CE Colour:Black Material:Aluminum Alloy Size: 121x51x43mm Package Contents: 1x Headphone Amplifier 1x USB A/C to USB C Cable 1x User Manual(English) 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.