Neodymium Magnets a rare earth metal offering exceptional strength to performance ratio, found only in the most exotic speakers, saves tremendous weight. Don't let the sound system weigh your vehicle down..Carbon Composite Basket based on the spokes of a wheel is lightweight, will not flex during peaks and looks great! Don't be afraid to show off the back of your woofer..Klippel Optimized Components using a state-of-the-art Klippel Distortion Analyzer, Polk engineers were able to optimize the woofer's motor structure, voice coil alignment and suspension for the best possible performance, even at extreme listening levels..Woven Glass Composite Cones feature tremendous stiffness-tomass ratio. Lower mass means faster transients and finer detail..Large-Diameter Voice Coils (30mm) in drivers increase reliability and power handling capacity. Introducing the new Mobile Monitor (MM) Series high performance loudspeaker systems, the next generation in mobile loudspeaker design. The MM Series features 18 new models, including 3 Ultra Marine designs, to fit virtually any application on land and water. The MM Series is composed of 6 full range systems, 3 component packages and 9 subwoofers. As a result of 3 years of Polk research and development, the new MM systems have been designed to offer unparalleled sound quality with exceptional fit to meet virtually any application. Borrowing technology from our flagship SR Series, the MM Series offers exceptional value for the price. Through the use of high-tech carbon composite baskets, powerful Neodymium motor structures using oversized voice coils, and state-of-the-art woven glass composite cones, we offer high-end audio performance normally found only in the most expensive loudspeaker systems. In addition, these space age materials offer weight savings that can mean higher performance for your car or boat.