Strap for Diver - same as AP 44mm

[FEINT]

I am wanting to get a new rubber strap for my ROO Diver 42mm, I just need a sanity check that I understand this correctly.

I need a strap thats 28mm (lug end) that tapers to 24mm (buckle end)?

I also read it was 30mm which has probably confused me.

Does anyone have a guide or spec sheet on what constitutes a standard length , Small or large size strap?

My wrist is approximately 17cm or 6.7 inch.

Thanks heaps