Polk Audio DB 6500 6.5-Inch 2-Way Vehicle Speaker (Single, Silver) A single unit marine-certified vehicle speaker system with 2 main speakers, 1 tweeter, and an external crossover Two 6.5-inch, dynamic balance, polymer/mica composite cone woofers One 1-inch silk/polymer composite dome tweeter with versatile surface and flush mount swivel cups Frequency response: 40 Hz to 22 kHz Mounting cutout diameter of 5-inches for speakers and 2-inches for tweeter