case diameter of PO

[kfmx]

just bought my first omega and its a PO XL 45.5mm

went back to measure bezel diameter 9 to 3 o'clock but its nowhere near 45.5mm

how do we accurately measure the PO case diameter?

thanks.

[Fred the Red Devil]

I am also puzzled... Its ard 43mm if I measure bezel to bezel for my PO XL. Any seniors would like to advise?