Features: 1. Ergonomic design, perfect fit in the ear canal, comfortable and stress-free, enjoy. 2. The high-sensitivity microphone allows you to receive sound perfectly and enjoy high-definition calls. 3. One-button remote control allows you to switch songs/calls freely. 4. Professional earphones, made of high-quality materials, with better elasticity and softer feel. 5. Smartly compatible with all Andriod and IOS mobile phones, and other audio devices such as tablets, computers, PCs, mp3 mp4 mp5 players. Notes: 1. Due to the lighting effects and shooting angles, there is a color difference in the product, please understand. 2. Due to manual measurement, there is a tolerance in the product size. Specification: Model: D21 Headphone type: in-ear headphones Wearing method: earplugs Headphone output audio source: Universal Plug diameter: 3.5mm Plug Type: Straight Plug Whether wireless headset: wired headset With or without a microphone: yes Sound principle: moving coil Frequency response range: 20-2000 (Hz) Impedance: 32 () Sensitivity: 98 (dB) Distortion rate: 2 (%) Wire length: 1 (m) Horn diameter: 10 (mm) Earplug/earmuff material: Silicone Headphone cable material: TPU