The Vintage Wrist Watch Company has dated this piece to the 1920s.
The chain measures 35mm long including the T-bar and the clasp.

Also included is a silver fob with enamel detailing to the front. The fob is hallmarked for Birmingham 1934, and it also has the special hallmark to commemorate the Silver Jubilee of King George V and Queen Mary.
Total weight 30.6g.
The chain came to us in a small leather covered box so we are including it in the sale.
The Vintage Wrist Watch Company has dated this piece to the 1920s.
Specialists in antique and vintage wrist watches and pocket watches
You can view the stock and full dealer information on the The Vintage Wrist Watch Company Profile Page