K-Series coaxials feature titanium coated polygraphite cones and titanium-deposited neodymium tweeters for the perfect combination of stunning highs and powerful bass, even when you crank up the volume. The ribbed foam surround not only looks cool, they borrow technology from KICKER's Comp VR subwoofers to offer precise control during extreme cone excursion. KICKER K-Series speakers are designed for a no problem fit into the majority of factory speaker locations.- Titanium Finish Polygraphite Cones. - Polyester Ribbed Foam Surround. - 1" Kaladax (polyethylene naphthalate film) Neodymium Dome Tweeters.