HISTORICAL RELEVANCE
The round collar style has been a part of the Eton school uniform since the mid-nineteenth century. The collar started as a seperate white collar that attached to the shirt, early on the collar was a mark of membership to an exclusive male club... hence "club" collar. This is certainly a more dapper look. According to Alan Flusser this may not be appropriate for men with round faces.
EXACT SPECIFICATIONS
2 3/8" collar point length, 3" spread, 1 1/8" front collar band height, 1 3/8" rear collar band height, 3/8" tie space, rounded collar points.