The NHT O2-ARC is a unique, high-performance outdoor loudspeaker like no other. Sold as singles, the O2-ARC is not only weather (UV) and moisture resistant, it is specifically tuned to sound just right out there in nature where there are no walls except the one the speaker is nailed to. The O2-ARC includes a time-tested 1-inch treated silk dome, fluid-cooled, UV-treated tweeter that is working together with a robust 6.5-inch midrange-woofer mounted in a traditional NHT sealed box system. The O2-ARC enclosure features NHT's newest material technology: Anti-Resonant Casting or ARC. The ARC enclosure provides unprecedented strength and several lifetimes of durability while it acoustically kills the vibrations of the box itself to inaudible levels. The O2-ARC is available in white or black matte finish and include the mounting bracket.