Perfect tuning requires patience and understanding Cayin Quad Balanced Armature system is constructed with dual Knowles and dual Sonion high definition balanced armature drivers, with carefully tuned crossover design. Outstanding clarity and musicality across the complete frequency band delivers subtle and intimated emotion from every note. Exceptional quality machined CNC aluminium enclosures The CNC aluminium enclosures are made from a solid build quality with a robust matt finishing and a jointless structure in order to reduce resonance and rippling effect between drivers. Custom-developed housing and curvature for comfort, isolation and secure wearing with angled nozzle to fit the earpiece into the ears naturally. The extremely strong aluminium nozzle is removable to easily clean and maintain your earpieces. Custom built “Highway” to fidelity - 8-wire hybrid design cable To bring out the best audio performance from the YB04, Cayin have made an 8-wire hybrid design cable using a special annealing and recrystallization process. It has superior ductility and flexibility with minimal stethoscope effect. Connectivity for serious users High Quality 3.5mm gold plated connector, resistant to corrosion or oxidation with soft mating surfaces to increase contact area. It will help maintain good connections and minimize transmission loss over time. The hexagon design aluminium splitter and connector has been casted from custom mould and maintain a high level of conformity with the faceplate of the earpiece. YB04 uses gold-plated 0.78mm 2-pin connectors in a non-recessed extruded design with maximum compatibility and robustness.