I have a non Skyfall/Skyfall PO 42 MM (Insert long, confusing model number here) and want to know the best fit OEM NATO.

 

20mm, for the first and second PO. 2500/8500. If you have one of them.
Or do you mean it's not the branded Skyfall Ltd Ed, but is still the 8500. Either way, you need a 20mm

 

Reason I ask is because they say 19-20mm as a selection. Dose that mean it is 19 or 20 mm?

 

It's 20mm, but if you order an OEM it's the 19/20 size yes

 

No you get the 21mm one and curved springbars.

 

I've asked those questions about curved springbars at OMEGA Bond St and Regent St each time I purchased 3 different straps over the last couple of years. They sell them with straight bars for the PO. What are you using curved with a 21-22mm on?

 

The straps are 19mm or 21mm

I run the 21 on a speedy pro.

 

What's the benefit of curved, does it sit flatter on the wrist?

 

I have tried to put the leather 19mm strap from my Speedy Trilogy on my professional. 19mm leather is too narrow. Too much space between the lugs and so a risk that the strap will stick behind the pin and possible to pull it out. My advice is always the 20mm

 

Good choice, 19mm is way too narrow. Too much space left

 

It fits a bit cleaner with the slightly oversized strap. The curve takes away the bunching.

 

I've a couple of PO, and a dozen NATO, all 20mm. They work fine with the bracelet pins. I only use longer pins on the rubbers, but I've never tried curved, but if you don't use curved, the OEM 20 are fine.

 

The oem 19-20mm strap is 19.5mm wide, and the 21-22mm strap is 21.5mm wide.
When I first got my 21.5mm wide strap on my POC, I went back to the boutique to make sure it is the right size, as I could see the springbars.

 

Mostly for when the clearance between the spring bar and case is too tight for the NATO to fit

 

In all the years of owning the 42mm/20mm PO, which is well over 10 years, not one 19.5 OEM NATO or 3rd Party 20mm has ever shown 1 mm of springbar. What are they touting for the new Mark 3 PO lugs now?

That makes sense

 

I have a ton of aftermarket 20mm NATO I use and they fit perfect FWIW

 

That was my first reply...