Contact our Team

Do you want to be one of the first to get our products when they are ready for sale? Would you like to become our business partner? Do you have some open questions? Then please feel free to contact us—We look forward to hearing from you! (Our team is able to answer your requests in English and German.)

Contact Data

TETRAGON Braille Systems GmbH
Bennoplatz 4/2/9
1080 Vienna
(no office)

+43 681 20652038
(on work days from 9am until 5pm CET)

Please note that we do not have an office at this address! You can use this address to send us mail, but if you would like to meet us in person, please contact us first so that we can arrange a convenient time and place to meet.

The phone number will connect you with our founder Wolfgang Zagler.

You can also send an email to a specific team member by using the pattern


Wolfgang Zagler (Dipl.-Ing. Dr.)
Accessibility Design

Wolfgang Zagler is a retired professor, who had his own working group for Assisting Technologies at TU Wien. He has decades of experience with Braille displays and supervised two master’s theses in which the concept for our first product was developed. Even in his retirement, he is eager to bring new assistive inventions to life.

Wolfgang Zagler on LinkedIn

Wolfgang Zagler

Michael Treml (Dipl.-Ing.)
Software Engineering

Michael Treml studied Media Informatics. In his masters’s thesis, he came up with the initial BrailleRing idea of combining grouped Braille dots in a rotating ring. He is currently working on his doctoral thesis in the field of technology-assisted braille teaching.

Michael Treml on LinkedIn

Michael Treml

Dominik Busse (Dipl.-Ing.)

Dominik Busse studied Mechanical Engineering, specializing in lighweight structures and applied machine elements. He has been designing and building prototypes for TETRAGON since his master’s thesis.

Dominik Busse on LinkedIn

Dominik Busse

Mike Busboom (B.A.)
Braille Consultant

Mike Busboom is an expert in Braille reading. Being blind himself, he is TETRAGON’s most important link to the blind community. He has more than 20 years of experience in marketing refreshable Braille displays and he was also consulting Wolfgang Zagler's working group at TU Wien.

Mike Busboom

Other Team Members

Matthias Gerwinat (Ing. Mag.)
Managing Director

Matthias Gerwinat studied Industrial Engineering and Commercial Science. He has many years of experience as a managing director and a founder himself. Now he is also providing his experience to TETRAGON.

Matthias Gerwinat on LinkedIn

Matthias Gerwinat

Georg Ehrenfels

Georg Ehrenfels learned the job of a watchmaker and is an expert in precision mechanics. He was part of Wolfgang Zagler's working group and has been involved in the assembly of our mockups and prototypes since the early stages.

Georg Ehrenfels

Various Tasks

Our strong ties to TU Wien and other universities allow us to work with many students who are writing their theses in the field of Braille technology. While we cannot list all of them individually, we would like to acknowledge their work for TETRAGON with this general entry.