Howe's UJ-1818 runs 1"-48 spline straight through, so it connects two shafts with the same end.
- End 1: 1"-48 spline (code 18)
- End 2: 1"-48 spline (code 18)
Howe lists this joint family in a long list of spline combinations, so if your ends are different, check the other UJ part numbers.
Howe Performance part number UJ-1818.