2 breaker bars because one holds the hex shamed harmonic balancer tool which keeps it from moving and the motor from spinning and the other breaker bar is for the nut on the harmonic balancer. that's why when you look at a honda's harmonic balancer there's a big hex indentation around the nut, it's for that hollow tool to go so you can hold it in place while through the middle of it you put your socket and spin the nut off.