
All my inline filters use 1/4" quick disconnects. It's 1/2" FNPT. I've added pictures to show my fittings used. I would discard these filters as they have the wrong labels on them.

NANPU 1 FRL Air Filter Regulator Lubricator Combo With 0-150 Psi Gauge, 5 Micron Brass Element, Poly Bowl & Semi-Auto Drain - Metal Bracket Included
20 Review

NANPU 3/8" NPT Compressed Air Filter Regulator Combo Piggyback, 5 Micron Brass Element, Poly Bowl, Semi-Auto Drain, Metal Bracket, 0-150 Psi Gauge
26 Review

Filter under the sink Aquaphor Favorit ECO silver
20 Review

NANPU Compressed Air Filter Regulator Combo: Brass Element, Semi-Auto Drain, 0-150 Psi Gauge, And More
21 Review