This video does a good job explaining the box and how it works. The guy is a bit of a nut, but breaks it down enough.
https://www.google.com/search?q=how...ate=ive&vld=cid:f26f5996,vid:AeXj35aOK7k,st:0
https://www.google.com/search?q=how...ate=ive&vld=cid:f26f5996,vid:AeXj35aOK7k,st:0