Features: Featuring one 3.5mm input and four 3.5mm outputs, the TM400 stereo mixer is capable of mixing signals from CD players, musical instruments, portable recording equipment, video playback equipment, and more. Small and sophisticated, the passive circuit design does not boost or degrade the audio signal. The TM400 works without batteries or external power supply, and is easy to carry and use any for time, anywhere. 4 main output volume knob and 1 independent input volume knobs, the 4 outputs do not interfere with each other. Provides the highest sound quality even at maximum output levels. Specifications: Material:PCB+Acrylic for Shell Size:Approx.83.5x54x21mm / 3.29x2.13x0.83in Color:Black Package Includes: 1x TM400 Line Mixer note: Please allow 1-2cm errors due to manual measurement,pls make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.