Laminate-Treated paper Cone - Advanced laminating process produces excellent stiffness to weight ratio, superior damping qualities. 19mm Balanced Drive Mylar Tweeter - Excellent reproduction of high frequencies. Polymide Voice Coil Former - High temperature light-weight voice coil structure for increased sensitivity. Triple-Layer UV Treated Foam Surround - Premium design for excellent sensitivity and long-term reliability. Rigid Powder Coated Steel-Frame - Designed for precise motor alignment.