old beer mug 1L pressed glass with the bottom brand

•      Glass jar of a liter
•      Height 20 cm
•      Weight ca. 1413 g
•      No beer brand - just an empty cartridge for a beer brand or engraving or or or .....
•      At the bottom of a triangle with a circle in the center - thus it looks like 3 triangles - brand is unknown to us.
•      Pressed glass with 3 seams is usually very old - today pressed glass has 2 or even 4 seams - could be a glass of 1900

In a very good used condition with no chipping or cracks, have a look at the pictures.