Focal Polyglass 690 CVX 6 x 9-Inch Coaxial Speaker Kit Rotating and swivel mounted Aluminum inverted dome tweeter Polyglass cone made from hollow glass micro-spheres over a cellulose pulp, greatly increases rigidity of the cone without adding weight Built-in 12db/octave audiophile crossover One inch voice coil for high power handling Rigid, non-resonant molded frame that is easy to install