Brand Name: S.M.S.L Built-in Battery: No Recommended Headphone Maximum Impedance: 251-300 Ohm Output Type: LINE OUT (AUDIO OUT) Origin: CN(Origin) Input Type: RCA DSD (Direct Stream Digital): No Body Material: Aluminum Package: yes Channels: 2 (2.0) Output Power: 5.5w Model Number: SMSL SP100 Signal To Noise Ratio: 85 PCM: No Bluetooth: No Type: Mini Amplifier WIFI: No TYPE1: Tube Headphone Amplifier TYPE2: Tube Amplifier