Patek Philippe

Patek 5130 Strap Size

Hi all

Looking for a replacement strap for a 5130R World Timer

What kind of strap should i be looking for to match the original? shiny or matt brown alligator? light or dark?

And what size?

There must be so many straps out there and different kinds from Patek so not sure which to get

Currently using a black strap so dont know what the original is.

Thanks