Black on the front/ Brown on the back
You are looking at an INTERESTING version of the common American Flyer track terminal that hooks up your transformer (power pack) to the two rail American Flyer track. These are also used for some accessories.
This is the standard version with the Fahrenstock Clips.
But more importantly, THIS one is two colors: black on the front and brown on the back.
This one is clean but does have some use and some oxidation and signs of use. Ready to use.