Features: brand new and high quality Mini passive stereo mixer is a stereo four-way passive mixer for extended control tuning, mixing instrument, CD player, tape player, computer, mobile phone, tablet and so on. No battery or other power source required. The device can also be used as 1 In 4 Out stereo distributor clockwise to adjust the volume. OUTPUT: is used to connect RCA jack to mixer output or other output devices. IN 1-4: controls the signal level from input 1-4. 4 groups of stereo RCA input and 1 group of stereo RCA output, Four independently regulated 100K ohmic potentiometers. Specifications: Material:Metal Size:83x38x52mm/3.27x1.5x2.05in Color:Black Note: Please allow 1-2cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Passive Stereo Mixer