10mm High Polymer PET Diaphragm. It has good toughness, rigidity, fatigue resistance, rapid response speed, rich sound details, clear and delicate texture, achieving fine and accurate restoration of detail and phases. Dual Magnetic Circuit and Dual Cavity Design. The dynamic driver adds an independent back sound cavity, which can quickly accumulate and compress air to increase power, enhance sound explosiveness and detail performances. Exclusively Customized Appearance. Cavity is fully enclosed. High Density PC material is molded under a high pressure, which can well suppress diffuse reflection of the sound inside cavity. Material is skin friendly, simple and stylish , showing a sense of beauty and technology. 4 Core 4N Pure Copper Cable. KS1 is equipped with 4 core 4n pure copper wire, which enhances permeability to realize more textured low frequency, a better vocal, and a higher sound quality. Improved 2 Pin Plug. By analyzing various detachable cable interfaces in the industry and after complementing in a depth study of user experiences, a limit slot has been added to effectively protect the pin from breaking and extend product life. Earphone Specification : Interface : 2 Pin 0.78MM Frequency Response : 20 - 20kHz Sensitivity : 109 dB Impedance : 16 Ohm Cable Material : 4 Core 4N Pure Copper Cable