What’s a NATO Strap?
WuS has a great discussion of the NATO strap and it’s origins. NATO straps are traditionally nylon straps with a basic buckle and some have a “skunk stripe” down them for effect. These guys sell a few great ones.
The strap that collectors call “NATO” (not to be confused with the Rhino, Waterborne, or Maratec Zulu straps) is based upon the standard watch strap issued by the British Ministry of Defense (MOD). Called the “G10” by members of the British military because of the form used to requisition the strap (and other items) from inventory, the reason it got its “NATO” name is because the strap has a NSN or NATO Stock Number which identifies this type of strap. Incidentally, the actual military spec strap comes in only one color (Admiralty Grey) and one width (20mm). The hardware specs have not changed (chrome plated brass), though at least some of the straps currently issued have stainless steel fittings. And there are actually TWO NATO stock numbers for the straps: Army/Navy (6645-99-124-2986) and RAF (6645-99-527-7059). …
History of the “NATO” Strap [Watchuseek Watch Forums]