Stainless Steel Tube Fitting, 0.75 Inch Tube OD, Female JIC 37 deg Flare Sleeve

This stainless steel sleeve is made for tubing with a 0.75 inch outside diameter.

For 3/4 inch tube OD with a JIC 37 degree flare connection, yes this is the right sleeve. The J12S is made specifically for that tube size and flare angle, so it pairs with standard female JIC 37 degree flare fittings. Just make sure your tubing outside diameter is actually 3/4 inch before ordering, since tube OD and nominal pipe size are not the same thing.

The key spec is the tube OD. This sleeve is sized for 0.75 inch tube O D, so it matches a 3/4 inch tube outside diameter.

The key callouts are right in the name and attributes: it is a stainless steel tube sleeve for 0.75 inch tube OD, and it is for a female JIC 37 degree flare connection.