Vintage Circa 1930 Mens Jewelry Accessory Swank B&W Plate Collar Bar Stay, Gold Plated, Patent Number 75818. 

It is marked SWANK, B&W PLATE, and PAT NO. 75818 on the center piece. The patent 75818 was filed December 8, 1927, and granted July 24, 1928.

B&W stands for Baer & Wilde, which was Swank's trading name during the early 1900s. This piece was made during the transition of the company from being known as B&W to SWANK, which is a well known men's accessories brand today. 

This collectible men's fashion accessory is in very good vintage condition. Please see the photos for details and feel free to ask questions. I am happy to help!