9MM DYNAMIC DRIVERS: Engineered with 9mm high fidelity drivers??and the noise isolating in-ear design produce a excellent thumping bass.</br>ERGONOMIC EARPHONES DESIGN:Patented ergonomic earpiece design provides long-term wearing comfort.Perfect earphones for gym and outdoor sport.</br>SOUND QUALITY:JET-830's sensitivity of 20% higher than traditional headphones?? headphone impedance lower than the other 30%.It means that the problem of low power audio equipment can't play excellent music will be not exist.</br>COMPATIBLE WITH SMARTPHONE:Compatible with all 3.5 mm audio jack smartphones and devices.</br>1 YEAR WARRANTY (NOW $12.99 Special Holiday Time-limited Promotion Underway )</br></br>Product Description</br></br><b>About the Jayfi:</b><br> Jayfi in ear headphones created by JAYFI CREATIVITY??and JAYFI CREATIVITY keeping use unique manufacturing process to make the best tailor-made headset.<br> With many times of trial and error??JAYFI CREATIVITY developed the JET-830 to balance t