Blue Anodized Aluminum Adapter, -12 Male JIC 37 deg Flare To 3/4 Inch Male NPT, Straight

For connecting two different thread styles, this adapter is a straight -12 male JIC 37 degree flare on one end and a 3/4 inch male NPT pipe thread on the other.

On the JIC side, it is a -12 male 37 degree flare connection. The other end is a 3/4 inch male NPT (male pipe) thread. So it is meant to transition from a JIC 37 degree flare connection over to a 3/4 NPT female port.

That's exactly the job this fitting handles. One end is a -12 male JIC with the standard 37 degree flare, and the other is 3/4 inch male NPT, so you're going straight from your JIC line into that NPT port in a single piece. No reducers, no unions, no extra connections stacked in the middle.

This Eaton Aeroquip adapter is indeed designed for that exact purpose – connecting a -12 male JIC 37-degree flare to a 3/4 inch male NPT fitting.