YoeborStainless Steel 304 Compression Tube Fitting Straight Adapter Connector with Double Ferrules 3/8" OD x 1/4" NPT Male, Pack of 2

Seem like decent quality. Checked the 1/4" npt threads and they fit in the fuel pump properly. Metal shavings from machining process were wedged down tight inside and I almost didn't notice. Check yours before using!

Sorry tried using this on a steel fuel line. The 2-piece compression sleeve cones would nit seal and fuel literally sprayed out from the compression nut around the fuel line. No amount of tightening would stop the leak. It has 1 cone the seals the inlet and a second small cone to seal the back of the first. I tightened with wrenches and could get it to stop leaking. I went to the hardware store and bought a standard brass compression sleeve and reused the fitting. Didn’t leak a drop after using a the one-piece brass compression ring.