With the International Student Identity Card (ISIC) you can save money in various shops and restaurants in over 130 countries, travel cheaply and identify yourself internationally as a student. In addition, you can now use the ISIC quite easily via app.
The issuing of international student identity cards (ISIC) is possible in the AStA secretariat. The validity period is one year. To apply for a current colored passport photo (size 3 cm high and 2,5 cm wide) and the personal and student ID card is required. The cost is 18 euros for one year.
Further information at https://www.isic.de/