A long-sweep, low angle wye designed to more reliably feed full length darts through hoppers. There is also internally a guide to keeps the dart heads from lodging themselves in the bottom portion, similar to Captain Slug's "Knifty Wye" setup. The coupler portions are .848" ID to fit anything the same size as 1/2" SCH40 PVC. Depending on your printer you may need to scale a few degrees to get the dimensions just right. Should be able to print it standing upright on the single end without any necessary supports.