Paul mentioned a fuel filter with screw in adapter fittings -5/16th or 3/8th. I've been looking for that filter but haven't been able to find one.
there are models made by Spectre, Mr Gasket and Moeller. Plus many others I would assume.
They're just cheap imported items, but they have always done the job for me.
In some discussions the person answering the questions online stated that the clear portion was glass. Well if it's glass, it's not like any normal glass I know of. But hey, I'm no glass expert, so I can't say they're wrong. I've hit mine pretty hard and they just bounced. I don't try to break them, but they sure feel like poly-carb, or other plastic to me.
The fittings are just nylon, so while they are pretty reliable if you don't over-tighten them, I would not use them as the sole support for the filter either. Too much bouncing around would probably end up cracking one, but with the filter well supported they should not fail. A typical mounting point up on the intake is plenty of support, but I would not hang it out in space and rely on the tubing for the long-term.
The various ratings I've seen show the filters as anywhere from 40 to 120 microns! That's not very fine, but probably enough to do the job if your system is not already super dirty.
The Moeller brand claims 20microns, which is still not super-fine I don't think, but it's better than the others and has a PSI rating of 85 where the others just say they're for carburetors and do not give an actual psi rating.
There are others that have metal filter bodies and AN fittings, but the ones I saw start at 3/8" (-6 AN) and go up from there.
The best type of clear filter would be the poly-carbonate body with the metal ends, but those usually come with only one size fitting so you'd have to buy two filters to make it work. One 5/16 and the other 3/8 and swap one end for the other. I just used the plastic ones and never had a problem.
Paul