Beryllium Drivers: Beryllium is the ultimate material to deliver high frequency detail with extremely low distortion. Beryllium is seven times more rigid than aluminum or titanium, while being lighter than either material. This results in an extended, detailed high frequency response that reveals even the tiniest sonic details.Natural Wood Housing: The MP20 is encased in a natural wood housing made from sapele and features a small port to deliver an expansive soundstage and sonic fidelity. Some of the finest acoustic instruments are made from natural wood - why not your earphones?Comfort: The MP20 comes with small, medium, and large silicon ear tips to make sure you find the perfect fit and seal for noise isolation from the surrounding environment. A generous 4-foot earphone cable and travel bag are also supplied.Buy with Confidence: Monoprice not only stands behind every product we sell with a 1 year replacement warranty, we offer a 30-day money back guarantee as well! If the product you purchase does not satisfy your needs, send it back for a full refund.Quality at a Fair Price: Monoprice's rugged design and rigid quality control standards deliver high quality products at fair prices.