Sony XSGT1325A 5.25-Inch Coaxial 2-way Speakers (Discontinued by Manufacturer) 5-1/8 HOP Woofer Cone 1-7/16 H.D.L.D. High Density Layered Diaphragm 4-Ohms Nominal Impedance HOP (Highly Oriented Polyolefine) Cone Material