5.25" Premium 2-Way coax speakers with 1"" Magnesium WideSphere Technology Tweeters with pop aerated paper cone with a Mica blend. Magnesium Dome Tweeters 1” magnesium dome tweeter for exceptional musical reproduction of high frequencies WideSphere Technology Tunable waveguide tweeter housing with removable phase lens and an off-axis dispersion pattern from WideSphere work in tadem to create a larger sound stage that can be aimed with the waveguide adjustment Curvilinear Cone Lightweight aerated pop paper cone a with Mica blend for strength and superior bass frequency reproduction Low Resonant Frame Aerospace grade PA66 composite with 30% glass fiber speaker frame to assure that no harmonic distortions affect the tone of the speaker Audiophile Crossover The crossover network, which guides the frequencies to each driver, is designed with tight tolerance components for superb sound quality Designed to Fit MB Quart engineers work closely with vehicle designers to assure a perfect fit of every speaker, whether upgrading or doing a full custom installation