1. In terms of materials, high-quality raw materials are used to that they meet safety standards and are durable2. In terms of technology, the technology adopts excellent production standards, so that the sound quality of the audio can be better presented3. In terms of performance, the performance has a of music, and the three-frequency connection is smooth and the sound field is more relaxed and natural.4. Green environmental protection supports SGS, R0HS, REACH certification. safety, non- and radiation-free, green and environmentally friendly, safe to useProduct DescriptionModel: 4090Shape: roundComposition : single paper coneDiaphragm material: non-paperMagnetic circuit form: external magnetic typeFrequency characteristics: full frequency band (full range)Rated power: 20m (W)Rated impedance: 3215% ()Frequency response: 50-10 (kHz)Sensitivity: 118.53dB (dB/W)Harmonic distortion: 3% (TMD%)Color: BlackMaterial: metalPackage Contents:2 x headphone speakersOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.