Built-in Battery : NoCertification : CERecommended Headphone Maximum Impedance : <32 OhmOutput Type : USBInput Type : RCADSD (Direct Stream Digital) : NoBody Material : MetalPackage : YESModel Number : type c connector to earphone jackBluetooth : NoType : Mini AmplifierWIFI : NoAudio Adapter 3.5mm Earphone Jack Digital Converter Type C Audio interface DAC Hi Fi for Mobile phone Headphone Amplifier