Features: HP401 DC5V-12V Stereo auditory Mixer 4 Input 1 output Individually Controls Board Sound mixing Headphones Amplifier Stereo four-way auditory input is mixed into one stereo output, which can directly drive headphones or connect to a power amplifier 3.5mm headphone connection, and potentiometers to individually control the sound channel not affecting each other. The power supply is to 12V, and the magnification is about 2 times. and the maximum driving current is 70ma, which can easily drive various earphones and external power amplifiers. Please use low rippled power supply. For auditory cables, please use shielded cables. The power connection is ordinary DC5.5x2.1mm. Specifications: Power supply: to DC12V Maximum output current: 70mA Magnification: 2 times Input: 4 channel Output: 1 channel Size：about 11.4x6.3x6.4CM/4.49x2.48x2.52in Package Includes: 1PC Headphone Amplifier 1PC Cable note: Please allow 1-2cm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual color.