Breakout Box and Tops offs

I just barely learned about this feature.  The box is pretty cheap, but can you explain to me the basics of how this works?  I'm actually having a hard time finding information on it and how to do it. I've noticed that people will get 3 or 4 sensors to hook it up.  1 for high, average and low water level and 1 for the over flows if they are doing herbie's.  Possibly link me to the float valves you used as well?  I was going to PM you, but I figured there might be someone else that may want to see how this works.