That actually makes sense, design-wise. Line in the middle is usually where some verbage or a manufacturer name is. And the two dots on either side are the stopping points (small bars sticking out) to keep the needle from moving too far in either direction and damaging the meter.

your current filter.Goody for you. Maybe someone else will read it and learn something they didn’t know.
I hope you’re not as charming with all of your replies to random people.
Translation: I don’t care.
I fear for your intelligence and/or future learning capability if three sentences is tl;dr.
TL;DR
That actually makes sense, design-wise. Line in the middle is usually where some verbage or a manufacturer name is. And the two dots on either side are the stopping points (small bars sticking out) to keep the needle from moving too far in either direction and damaging the meter.
Edited
They look so uncanny I’m sorta both creeped out and laughing at the sametime.

your current filter.