I added this today while home recovering from Wuhans. The filter is rated 95%, 140 microns, per SAE J1985 test. Pretty cheap off of Amazon and a bunch of filters cross over, so shouldn't pose a problem traveling. https://shop.donaldson.com/store/en-us/product/P552203/1553#   The base is a standard cheap WIX 24770 universal unit. I drilled and tapped the frame 5/16" NF.   I wanted to put a shut-off valve on the tank side, but decided I can just pinch off the hose when the