1The air in the front end sound area and the back cavity of the horn can maintain pressure balance and reduce the pressure on the eardrum. 2Copper is used for transmission, with low resistance, low consumption and high sound fidelity. 3Skinfriendly resin material is comfortable when in contact with the skin, clean and hygienic. 4Resin material is durable and no discoloration, and has high stability, which makes the body present a crystal clear effect. 5Earbuds are easy to use, so you just need to plug them into your device and enjoy. Item Type: Resin Earbuds Wire Length: Approx. 120cm / 47.2in Wire Core Material: Oxygen-Free Copper Plug Type: L-Type Plug Diameter: Approx. 3.5mm / 0.1in Wire Type: hand-woven twisted thread Headphone Jack: 0.75/0.78 pin Sounding Principle: Moving Coil Speaker Impedance: 16 Speaker Diameter: Approx. 10mm / 0.4in Frequency Response Range: 20-20KHZ Sensitivity: 109dB Ear Shell Material: epoxy resin, one-piece molding Cavity Material: copper plated with gold 1 x Headphones 6 x Earplug