The Square D QO 100 Amp 8-Space 16-Circuit Fixed Main Lugs Indoor Load Center is UL listed for residential, commercial and industrial power distribution. This load center is built with a rugged themoplastic interior and an aluminum bus bar plated for reliability. QO load centers are tested and compatible with Square D QO standard circuit breakers adn CTL-type tandems. Square D QO load centers are the "World's Finest" designed with industry leading features for flexible application. QO breaker boxes include features engineered for fast installation and wire savings.