Product review (1 stars): Wrong size.
The top of the cap CLEARLY says "OEM 4037 1 1/4"."
I only have an electrical engineering degree... not a mechanical one. But when I see 1-1/4", I assume that would mean this should at least fit my 1-1/4" vent pipe from my oil tank. Even WITH the set screw cranked all the way down, this thing would blow off in the wind with my 1-1/4" pipe.

I got out my calipers. Since when does 1.68" = 1.25"? Or even 1.54" = 1.25? I shimmed the difference because I know how to force it to work, but I wouldn't buy this again.