1. No Electricity Required, Portable and Easy to Use The stereo mixer features a passive design that works without batteries or external power supplies. Its compact size and light weight make it very portable, allowing audio mixing anytime, anywhere. 2. Four Independent Volume Controls, NonDisturbing Channels Equipped with four individual input volume controls and a master output volume control, the volume of each channel can be adjusted independently without affecting the others. This design provides flexibility and precision when mixing signals and meets various audio processing requirements. 3. UltraLow Noise, Sound Quality By using quality components and a robust structure, the device delivers clear, distortion audio signals even at maximum output levels. The optimized input impedance (10K47K Ohm) and output impedance (2.5K10K Ohm) ensure stable audio transmission and exceptional sound performance. 4. Multiple Device Compatibility, Wide Application With four 3.5mm input interfaces and a 3.5mm output interface, it can be easily connected to various audio sources such as CD players, musical instruments, portable recording devices, and video players. Whether for live performances, recording sessions, or home entertainment, it delivers audio mixing results.