Many thanks Leonard - quite straightforward really. I was thrown by the 0.75 (thread pitch), can't see why anyone would bother to state that, especially if they are all the same.
There are a very few larger-diameter lenses which have "coarse" filter threads with a pitch larger than 0.75. The Tiffen (Mfr# 105CCLRUN) 105mm Coarse Thread Clear Uncoated Filter is larger, for example.
I think the reference is just caution.
|Sadiqur_Rahman by Sadiqur Rahman|
from Ain't Going to Work on Maggie's Farm no More
|Airborne by John Beavin|
from - How to respect the Flag and Anthem - (Portrait in Full Colours + A Border)