Help with overflow

[db8xjohn]

can someone tell me how this overflow system works and any pic behind the black box.
thanks

 

[bountyhunter23]

There are two holes in the bottom of the tank in each black box. one for the flow to the sump/fuge and one for return. Water flows over the top, and down into the sump, then a return pump returns it back up to the tank.

 

[db8xjohn]

let me get this right, 1 go to the sump and the other is the return? and thanks for the help