QO Load Centers offer premium features like QO breakers, ground arc fault interrupters and surge arresters. QO load centers are designed for residential and industrial use to protect electrical systems, equipment and people. Systems are single or three phase and have indoor and outdoor versions. QO Load Centers enable the use of a full complement of accessories. Indoor enclosures are designed to be rotated 180 degrees to accommodate top or bottom service entrance feed. This 2 pole mounting base is for use in a 125 A 1-phase main lug load center. QO mounting base has a 10 kA breaking capacity. For use in NEMA 1 indoor load centers. Mounting base will accept a wire range of 14 to 4 AWG copper or 12 AWG to 2 AWG aluminum wire. Base is UL listed.