Polk Audio Atrium 65SDI All-Weather Stereo Speaker (Single, Black) Single all weather speaker with 6.5-inch mineral-composite polyproplyene cone Dual 1-inch metalized dome tweeters with neodymium magnets Dual Input/Single Input switch combined with dual tweeter array Constructed of stainless steel and brass hardware for years of rustproof reliability Frequency response: 50 Hz to 20 kHz