Had this for rather a long time, and never been able to identify it. 13 cm tall to top of stopper, which has a cork inside it. 7 cm across the base. Mark underneath is under glaze and is blue. Condition is very good.
I think that is the Fürstenberg mark, a porcelain manufacturer in Lower Saxony, Germany. But contact C.S. Marshall at Porcelain Marks & More to confirm this.