[indy78]

I have the 42mm 232.30.42.21.01.001 and was considering the purchase of a rubber strap. What size are the lugs? Do I need a 20mm/18mm?

 

[Wetworks]

I have the 42mm 232.30.42.21.01.001 and was considering the purchase of a rubber strap. What size are the lugs? Do I need a 20mm/18mm?

I'd say a 20mm strap would be the correct one. Both of my SMPs are 20mm and I'm pretty sure the case is the same reference.