Knurled, wrench fits. O-Ring included. Stainless and Alumiunum. Fits both, the solvent trap body tubes that I make, and the original 4003 filters. Like, totally interchangeable and stuffs…
Picture may not be representative of thread types because I didn’t take a picture of every single one.
10-32 w/ drain hole and plug screw (-DHPS)
13/16-16 for use with S37SA Oil Filter Adapters. (-S37) It is compatible with all (not messed-up) 13/16-16 adapters on the market.
3/4-10 for M11 9mm (-3410)
7/8-9 for M10 .45acp (-789)
M26x1.5LH for, uh, anything that has that on it. Yugo PAP stuff like the M85, M92, and others. (-2615LH)
M24x1.5RH, found on a lot of AK-74s in 5.45×39 and 5.56×45. (-2415RH)
M22x0.75RH for Saiga 12 and some other 12ga boomsticks, Stainless ONLY. (-2275)