The Square D QO 200 Amp 30-Space 30-Circuit Convertible Main Lugs Indoor Plug-on Neutral Load Center is UL listed for residential, commercial and industrial power distribution. This load center is built with a shielded, copper bus bar that is plated for reliability. QO load centers are tested and listed only for QO circuit breakers. QO load centers are the “World’s Finest” designed with industry leading features for flexible application. QO load centers include features engineered for fast installation and wire savings. This product is convertible to a main breaker load center with the installation of QOM2 main breaker (sold separately).