Let's talk about fuel filters...

NAPA/Wix for 3/8 inline metal filter, you can’t see inside, but it’s cheap so change annually. I can’t remember NAPA number but Wix 33033

https://www.summitracing.com/parts/wix-33033?seid=srese2&utm_source=bing&utm_medium=cpc&utm_campaign=Brands+|+W&utm_term=4581871113176070&utm_content=GSAPI+5ba2a561ca240

As others said, 3/8=-6 AN, The way to do the math is take the AN number and put over 16. 6/16 = 3/8 inch, 8/16 = 1/2 inch