I just bought this unusual collar on Etsy at Hidden River Finds.

First mention of collar Clipped from The Morning News
Wilmington, Delaware
22 Apr 1911, Sat  •  Page 5 https://www.newspapers.com/clip/58031581/1911-mens-new-spring-neckwear-mentions/

First picture ad (Image below) Clipped from The Sedgwick Pantagraph
Sedgwick, Kansas
04 Jul 1912, Thu  •  Page 5

https://www.newspapers.com/clip/58032496/1912-ad-for-the-nassau-arrow-collar/