3.5mm Interface with 4Pole Support Compatible with headsets featuring builtin microphones for clear, natural voice calls on mobile phones. Includes an additional Qunlian interface option for versatile connectivity. Performance Audio Processing Equipped with a 7band sound equalizer and preamplifier gain for precise audio tuning. Powered by a 4580 classic operational amplifier delivering 5x amplification (14dB) for rich, detailed sound. Input impedance: 20K ohms; Output impedance: 600 ohms for signal transfer. Advanced Equalizer Control 7 adjustable frequency bands: 60Hz, 150Hz, 400Hz, 1KHz, 3KHz, 6.5KHz, 15KHz. ±12dB control range for finetuning bass, midrange, and treble response. Designed with quality TI or ST TL074 circuits for consistent performance and low noise. Versatile Headphone Compatibility Integrated NE5532 type 47 headphone driver circuit for powerful, clear audio output. Easily drives a wide range of headphone types, from impedance studio models to everyday listening devices. Adjustable and low sound settings for listening preferences. Comes with a quality sound cable for reliable, interference connection. Ideal Use Scenarios 1. for home audio enthusiasts seeking fine control over sound frequencies for music enjoyment. 2. Suitable for content creators and online meetings, ensuring clear voice transmission and optimized headphone audio. 3. for audio engineers and hobbyists who require precision equalization when working with different audio environments.