QO 60-Amp 4-Space 8-Circuit Generator Main Breaker Indoor Manual Transfer SwitchThe 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,