Mucro MB-232 Running In-Ear Sport Earhook Wired Stereo Headphones for Jogging Gym 1. Adjustable earhooks is easy to clip on your ear, then keep the headphone securely in place during sports & rigorous activity. 2. Silicone earplugs, comforms to your ear. These are 3 sizes of earplugs to ensure a custom comfortable fit, sealing the ear to deliver bass and isolate noises. 3. Good sound quality: good call quality and microphone. Even on a noisy treadmill, you can clearly hear each other. 4. Built-in microphone, can answer hang up calls and switch music 5. Suitable for all kinds of sports occasions, such as running, jogging, hiking, cycling, etc 6. 3.5mm headphone jack 7. Frequency range: 20-20KHz 8. Sensitivity: 97dB+-3dB 9. Impedance: 16+-15% ohm 10. Line length: 120+-5cm 11. Package list: - Mucro headphones x 1 - Earbuds x 2 pairs (ML) - Memory foam ear caps x 1 pair - Carrying case x 1 - User Manual x 1