Question on old Vivitar Series 1 lens

[Von Rottes]

Looking into the old Vivitar series 1 28-90 lens, but I keep seeing N/AI on the lens barrel.

I can't seem to find much info on anything other than the VMC 70-210
I know I can use pretty much any AI lens on my D5300, but does anyone know for sure if the VMC 28-90 is Non-AI or is it AI?