I've used these six packs and they filter the air. I don't have the equipment to measure these things, but I can subjectively say they seem to do the job. Indoor allergies aren't a big deal, dust turns them nasty grey, as you'd expect (Northern Colorado has all kinds). any air crap you can think of) and even in that case it's going to take quite a long time.
🔧 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 DFR-02 1/4" NPT Air Drying System - Double Air Filters, Air Pressure Regulator Combo - Semi-Auto Drain, Poly Bowl
20 Review
NANPU Air Drying System With Double Filters And Pressure Regulator Combo For Clean And Controlled Air Supply
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