QO load centers offer premium features by allowing QO breakers, ground arc fault interrupters arc fault interrupters and surge arresters to be installed inside These circuit breakers have an over center, trip free toggle mechanism with quick make, quick break action and positive handle indication. They also have VisiTrip trip indication, which provides a visual indication that the circuit breaker has tripped and interrupted the circuit. Indoor enclosures are designed to rotate 180 degrees to accommodate top or bottom service entrance feed which saves expensive service cable. Three spaces are required when this kit is used. Lugs will accept 12 AWG to 2/0 AWG aluminum or copper wire. The lug kit is UL component recognized and CSA certified.