All my in-line 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.
π§ NANPU 1/2" NPT Compressed Air Filter Regulator Combo Piggyback with Auto Drain, 5 Micron Brass Element, Poly Bowl, Metal Bracket, and 0-150 psi Gauge
18 Review
NANPU 1/2" NPT Air Drying System - 5 Micron Particulate Filter, 0.01 Micron Coalescing Filter, Air Pressure Regulator Combo - Semi-Auto Drain, Poly Bowl W/Metal Gauge
23 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