#16 MP X #12 FP Swivel 90*

Yeah, that's exactly what it does. The male end is #16 pipe thread and the female swivel end is #12 pipe thread, so it handles that size reduction right at the 90-degree turn. Brennan Industries makes this one, and it's a solid choice when you need to change both direction and thread size in the same connection without adding extra fittings in the line.