1[4 In 1 Out] Stereo mixer that mixes four sound inputs into one stereo output. Each potentiometer controls the volume of each channel separately and does not affect each other. 2[Easy To Control] Stereo sound mixer shell is made of premium metal, sturdy and decent switching device. With the bass and treble controls, you can adjust the settings as needed. 3[Long Range] 4 in 1 out mixer, direct drive for headphones or connection to amplifier, with 5mm stereo socket. With 5mm sound cable, providing long range transmission of inputs and outputs. 4[Compatible Devices] 5mm stereo mixer input interface compatible with PC, cell phones, laptops, etc. Output compatible with speakers, headphones, bar speakers and more devices. 5[Stable] Working voltage is DC 5V12V, DC5 x 1, amplification is about 2x. About 8ma quiescent current, using for NJM3414 low voltage high current op amp. Maximum drive current 70ma, easily drive headphones and external amplifiers.