I found a really nice Mother Russia NATO the has the colors of the Russian flag for my Russian watches in 20mm. But I also wanted 18mm because my Vostoks are 18 but no luck. Also found a nice yellow camo that would look good on my gold Vostok Komandirskie but only found 20mm from different sellers. They have the same strap in the same size-only 20mm. Why is this?