The Vintage Wrist Watch Company has dated this piece to the 1910s.
The chain measures 24.5cm long including the T-bar and the clasp.
Each of the links has the silver lion mark.

The chain comes with an enamel and white metal fob (probably silver but unhallmarked) with an image of St George and the Dragon to the one side, and the motto, ‘Let There Be Light’ to the other side, together with the initials to the centre.
Total weight 27.3g.
The Vintage Wrist Watch Company has dated this piece to the 1910s.
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