Don't have a caliper but on my metric ruler it looks like the Konig center cap "coin" is 50mm. 49mm might be ideal if somebody was going to have something machined, 3d printed or stickers made. 50mm should fit in the recess though I think.
When I used my calipers to measure them before installation on the car, they came out to 48.5mm.
I am still a bit ambivalent about getting another set of (satin black this time) Dekas over the yes, crazy exorbitant $$$ Braids.
IF I could be
guaranteed that I would NOT lose that
prepaid $1700.00, if the distributor for these things goes out of business, due to the current crisis, before the wheels show up in 4-7 months time, I would say eff it, and go for them (or if Braid
themselves guaranteed me this).