The glass is broken but one day due to inattention on my part.
Since I work in a chemical laboratory, I noticed that the glass is identical as a 1L beaker high form. The dimensions of this beaker are standardized according to DIN 12331 and ISO 3819. It costs from € 6 the internet. Terms of quality, it is also identical (borosilicate glass), absolutely heat resistant, even m. E. practical since the grading is available.
Addendum: When filling the pot to about 1 cm below the silver ring, there are 800 ml So the pot is enough for 3 cups of coffee..