Attwood louvered hull vents
I measured the openings in which these replacement vents were to go - they were rough and not clean, so I picked the vents closest to the openings I had.
After some time and grinding the openings larger, they were in, but a couple had to be forced and tapped in with a block of wood. Don't overtighten or they will crack near the screwholes.
End result was good.
Attwood Louvered Vents
Very good quality, my old Attwood vents were 20 years old, time for a change so I went with the chrome version, very shiny, dresses my whole boat up.
Exactly as described
Purchased as replacements for a boat renewal project.