dimensions of plastic inserts for 18mm front sight?

[gnm]

I have a bunch of plastic inserts for 18mm front sight that are flat plastic discs. They fit perfectly my my 1962 match 54 with 18mm front sight.

I also have a nice tinted insert that has a "step" - a wider outer diameter, and a "step" with smaller diameter. This insert is too loose in the front sight and the "step" is too loose in the fixing ring for the inserts. (not sure of the correct terminology).

Can someone please post the outer diameter and the "step" diameter of their inserts.

Thank you!

[High Left]

My FWB air rifle has a stepped insert. It's a 22mm, but for reference the diameters are .708/.782 ... 18/19.8mm.

[gnm]

Thanks, but I need 18mm stepped insert dimensions, not 22mm.

PS I edited the original post to make it clear that I am asking about inserts for 18mm front sight.

[High Left]

Yeah, might not scale by subtracting 4mm. Hence, 'reference'.

[gnm]

Still waiting for someone to post the dimensions...

Thank you.