Neoteck Portable 35Mm Headphone Amplifier With Bluetooth 50 Receiver, Two-Stage Gain Switch, 16-150 Ohm Hifi Earphone Amp, Aluminum Matte SurfaceAll Neoteck Product comes With 18 Months US Base Warranty Overview: This HiFi headphone amplifier design is normally used to drive a headphone with a relatively high impedance It can connect various audio ..