Incorrect description as the 1" thread on the filter housing is a machine thread, not NPT. So you can connect to 3 NPT male threads /4" thread ends only. But that's fine as you have the connector on either side and you can easily remove/replace the whole thing if needed. There are female threads in the machine thread ends as well as 3/4" NPT, but if you've used them, you'd have no connections. I've installed them before, albeit more expensive brands.
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
NANPU Compressed Air Filter Regulator Combo: Brass Element, Semi-Auto Drain, 0-150 Psi Gauge, And More
21 Review
Filter under the sink Aquaphor Favorit ECO silver
20 Review
NANPU DFR-02 1/4" NPT Air Drying System - Double Air Filters, Air Pressure Regulator Combo - Semi-Auto Drain, Poly Bowl
20 Review