Polk Audio Atrium 4 Outdoor Speakers (Pair, Black) Atrium Series Speakers exceed baseline industrial and military specifications for environmental endurance Anodized aluminum tweeter domes with rubber surrounds are absolutely immune to the elements, offer better power handling and smooth response Tweeter phase cap smooths the frequency response from 12KHz up to 20kHz, the last audible octave Broad coverage baffle design fills a large open outdoor space with big, full-range sound. A more steeply-angled baffle maximizes critical mid- and high-frequency dispersion over a large area, without sacrificing detail Speed-Lock Mounting System for easy, safe one-handed installations even in difficult locations; 5 years parts and labor