This transfer switch is built extremely well and comes with circuit breakers preinstalled. It can be used for 220 or 110 volt loads or a combination of both. Conduit and clamps were also included with this model. I really like the built in watt meters so I know how much of a load is being used on each bus. This switch makes having power available during an outage a breeze. Just start your generator and flip the desired circuit switches.