As far as I know, Omega has made 4 rubber straps for PO 2500 generation;
i.) 98000295 full orange, rounded profile, deployment clasp,
ii.) 98000292 black with orange stitching, rounded profile, deployment clasp,
iii.) 98000297 black with white stitching, rounded profile, deployment clasp,
iv.) 98000144 full black, squared profile, tang buckle.
Those all are parts numbers for 20mm straps, for sure there are similar staps for 45mm watches but but don't know respective parts numbers.
Enything else - orange or blue squared straps are aftermarket or fake.
Here are my 98000292 and 98000144 to visualize what I mean with the strap profile.
View attachment 1034425
The strap in your OP is 98000144 , do not confuse it with 98000085 which also is black 20mm rubber, but this is a strap for GMT Diver 300M model.
Click to expand...