Features: High Resolution Metamaterial Tuning System: HD metamaterial tuning system and sophisticated sound field control technology and advanced components are adopted, which can achieve a frequency response of about 20kHz, making you feel delicate music details as if you were in a concert hall.  Low Distortion, Balanced Sound Field Control Technology: The air circulation can be accurately controlled, so that the balance from low frequency to high frequency is realized, the distortion is effectively reduced, and the smooth and rich sound is presented.  Ergonomic Shape for Comfortable Wearing: We understand wearing comfort is one of the biggest concert for most in-ear earphones, thus we have paid high attention to this to present you a comfortable, secure fit and noise isolation earphone while it also possesses astonishing industrial design and beauty. ZAX2 could be the earphone on-the-go or something for professional scenario.  360° Stereo Surround Sound: It simulates and enhances the three-dimensional layering of ambient sound, brings 360 surround sound effect, realizes accurate sound positioning, and clearly judges the sound direction, so that users can take the lead in the game and win quickly.  New OFC Oxygen-free Copper Double Parallel Wire: High-quality ear wire is made by virtue of professional technology. The newly developed OFC oxygen-free copper double-parallel wire has excellent anti-interference and anti-noise ability, which can reduce signal loss as much as possible, and transmit accurate and natural sound.     Specifications: Product: ZX3.  Sensitivity: 109dB±3dB.  Inpedance: 17Ω±10%.  Frequency: 10hz-20khz.  Pin Type: 0.75mm.  Interface Type: 3.5mm.  Cable Length: 125±5 cm.     Package Included: 1 pair * Earphones.  1 * Braided cable.  3 pairs * Low Frequency Earplugs.  3 pairs * Equalizing Earplugs