Atrium 4 Outdoor Speakers series of Polk Audio exceed baseline industrial and military specifications for environmental endurance. The anodized aluminum tweeter domes with rubber surrounds are absolutely immune to the elements, offer better power handling and smooth response. Its tweeter phase cap smooths the frequency response from 12KHz up to 20kHz the maximum audible octave. The broad coverage baffle design of speakeers 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. It has speed-Lock mounting system for easy, safe one-handed installations even in difficult locations.