Lancaster Antiques has dated this piece to the 1910s.
They measure individually: 20cm in width, approximately 15.5cm in length from the wall fitting, and the back plate is 8cm in diameter.

The crystal drops have had new brass pins fitted to keep them in place.
Lancaster Antiques has dated this piece to the 1910s.
You can view the stock and full dealer information on the Lancaster Antiques Profile Page