The Bose® 251B 251® Environmental Speakers deliver performance and reliability most conventional outdoor speakers and many indoor speakers simply cannot match. A patented multi-chamber enclosure helps deliver deep, rich lower notes without audible distortion. An innovative Articulated Array speaker design distributes sound over a larger listening area. Engineered to withstand snow, rain, salt, and temperature extremes of 158F (70C) to -40F (-40C). Weather-resistant mounting brackets and hardware included to allow for easy installation. Backed by a 5-year transferable warranty. Compatible with amplifiers and receivers rated from 10 to 200 watts per channel.