Accucraft Ride-on, The universal coupler box is designed for equipment that gets used with 2.5, 1.6, and 1.5 scales.  It allows the use of either a 2.5 coupler (in the top box) and a 1.6/1.5 coupler (in the bottom box).  When the box is mounted at the correct hight for one size, the other will be at its correct hight.   This is a great way to make equipment compatible with either coupler sizes. A good use is make two adapter cars with one of each coupler on either end.  Just swap the cars around as needed to have either a string for 2.5 or 1.5/1.6 locomotives.  
 
Includes pin for 1.5/1.6" coupler.