The QO 60-Amp 4-Space 8-Circuit Generator Panel is intended to switch between utility power and a standby power source. The panel can accommodate overhead or underground feed with 1-1/2 in. maximum knockouts in the top and bottom end walls. The generator panel features 2 factory-installed main circuit breakers and a mechanical interlock to help ensure that only 1 main circuit breaker is in the on position at any time. In the event of power outages, the Square D QO Generator Panel is the ideal way to safely connect specific circuits in the home to an alternate power source, allowing for uninterrupted service.