Cap for rain barrel diverter

I managed to lose one of the caps for a diverter on our downspout that feeds our rain barrels. Without the cap, water doesn't go down the downspout into the drain tile in winter (or into the rainbarrel in summer, if both outlets from the diverter aren't in use). So here's a printed version for a replacement cap - 1.375" OD, 1.34" ID.