Bonn, Germany, from 1882.
From Organ Database Builders editor Stephen Hall, October 18, 2019. —
Klais Orgelbau is a German firm that designs, builds and restores pipe organs. It is a family run company, founded in 1882 by Johannes Klais senior and is now directed by his great-grandson Philipp Klais. The firm is based in Bonn, Germany. They have exported at least nine instruments to the United States.