Quad-BA Structure Per Side｜3-way Electronic Crossover | Knowles Non-damper High Performance Bass | Sonion Customized Full-ranged BA | Knowles Hi-res Tweeter 3-way Independent Acoustic Chamber | Medical Level 3D Printing | Fine CNC Machinery Fully Enclosed Isolation Design | Ergonomic Earpiece Shape and Size | High Purity OCC Copper | Fully-balanced Litz Wire | 0.78 Two-pin Cable Socket | 26 db Noise-reduction

Best match: Yvain + HC1 plug for Cu4 and Cu4 Cable