BQEYZ Earphone Spring 2 IEM In-Ear Monitor 9 Layer Piezoelectric Ceramic DD Coaxial All-in-One BA 0.78mm Single Crystal Copper CNC Aluminum Case

In-house manufactured custom driver: Tri-hybrid technology of 13mm coaxial dynamic driver + 9-layer piezo + balanced armature provides more powerful sound with high precision and high resolution. Frequency transition: Unique. Featuring crossover technology, which allows for smooth frequency transitions from one driver to another.Frequency Transitions: Custom designed in-house, the Spring 2 features smooth frequency transitions from one driver to another. Designed with a 5-axis CNC machined aluminum shell for ergonomic comfort. The black version has a red faceplate, but there is also a green version that has a red faceplate. Upgradable Cable: The Spring 2 IEM has a 0.78mm 2-pin connector with a matching attached detachable 224-core monocrystalline cable. I am using copper cable. In addition to the cable, it also comes with a leather carrying case, silicone ear tips, and a cleaning brush. Drive Capacity: The combination of extremely low 32 ohm impedance and high 110 dB sensitivity makes the Spring 2 a fairly efficient IEM. , making it the perfect portable listening companion for many smartphone users.