QO Circuit Breaker Load Centers, PK4GTA, from Square D are Underwriters Laboratories (UL) Listed and CSA rated panelboards. They are designed to meet residential, commercial, and industrial requirements to protect electrical systems, equipment, and people. 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. QO Load Centers feature plated copper bus, providing superior performance and durability. This QO Load Center accessory is grounding bar kit. This grounding bar is UL component recognized and CSA certified.