Through precise circuit acoustic tuning. VG4 has 9 switching tuning styles, high frequency extension, medium frequency density and low frequency diving, to meet the requirements of different hearing sense and different music styles. EnvisionTEC 3D printing equipment. Imported PMMA acrylic fiber friendly-skin material, they improved the high temperature resistance and shock resistance. Knowles + SONION balanced armature, more natural connection. Selected 2 Knowles +2 SONION balanced armature combination scheme, low-frequency and medium-frequency unit adopts the SONION 33AJ007 model, which provides low frequency with low distortion and atmosphere sense, and has the strength to be as good as balanced armature, Knowles electrostatic ED-26989 makes vocal more full, sweet and listenable. With the RAF-33518 high frequency unit, the high frequency density and ultra-high frequency extension are greatly improved to make the sound more balanced and natural. Electronic four-way crossover. A delicately processed electronic four-way crossover scheme, makes the four-unit balanced armature connect with each other The VG4 has a clear image, precise positioning and obvious layering, giving you a sense of hearing. The standard 6N high-purity 6N copper foil wire + silver foil wire can effectively reduce the distortion and loss caused by signal transmission, and make the sound more transparent and sound quality better. MMCX detachable cable design, high playability, long life. VG4 has been certified by the Japanese AUDIO association "Hi-Res AUDIO" to provide you with a listening experience beyond CD level. Specification: Drive unit: 4 balanced armature Rated power: 6mW Distortion rate: ≤0.5% (1kHz) Sensitivity: 115dB SPL/MW Channel balanced: ≤1dB Input impedance: 16 Ω Frequency response: 10Hz-40kHz Cable length: 1.2m ±5% Weight: about 4.2g per unit Plug: 3.5mm straight plug Waterproof: IPX3 Dustproof: IPX3