QO Load Centers offer premium features by allowing QO breakers, ground arc fault interrupters arc fault interrupters and surge arresters to be installed inside QO Load Centers enable the use of a full complement of accessories for your power needs. Systems can be single or three phase and have indoor and outdoor versions. Indoor enclosures are designed to rotate 180 degrees to accommodate top or bottom service entrance feed which saves expensive service cable. QO Load Centers feature plated copper bus, providing superior performance and durability. This QO Load Center accessory is a door cover used for a unit with 60 spaces. This system is for 60 spaces NEMA 1 enclosures.