Audiophile HiFi Bluetooth-compatible Headphone Amplifier Amplifier Receiver Features: Built-in high capacity battery Support charging over voltage protection Support high and low impedance earphone switch Support 16~600 impedance earphone Support output volume adjustment and bass adjustment Support one 3.5mm headphone port and one 3.5mm input port Support Bluetooth connection Type-c port for charging Aluminum alloy material, full of texture Specifications: Input port:3.5mmTRS Headphone port:3.5mmTRS Charging port:Type-c Bluetooth-compatible Version:BT 5.0 Built-in battery:3.7V/1400mA Charging voltage:5V/500mA Standby power:38mA Maximum working current:250mA Duration:6 hours 16heaphone power:110 mW 32heaphone power:105 mW 150heaphone power:6 5mW 300heaphone power:35 mW 600heaphone power:20 mW Maximum output Vp-p:9.9Vp-p THD+N:0.02% Signal to noise ratio:100db Frequency response:20hz20Khz Cross talk:100db Sound balance:0.3db Bare size:104.5x63.5x16.5mm Bare weight:146.5 g Working environment temperature:-20 to +60 Shell material:Aluminum Alloy Package Included: 1 pcs HIFI Headphone Amplifier 1 pcs 3.5mm Audio Cable 1 pcs Charging Cable 1 pcs User Manual