All sockets is stereo 3.5mm, input one way, both 2 ways output is same.And input two at the same time, then output be the mixed sound. Two inputs can input two different sound sources at the same time, and plug in at the same time not affect each other. The output is also, You can connect two headphones or two amplifiers at the same time. The first stage OP AMP is NJM4580, and the second stage driver is NJM4556A high-current operational Working voltage:DC 5-20V Colour:black Material:Metal Package Contents: 1 x Stereo Mixer Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.