We are a venerable company from the City of Schwalmstadt in northern Hessen, Germany.

Our company was founded in 1938 as "TREYSIT-Presserei" by Heinrich Ermel in Treysa (today a district of Schwalmstadt).
In the beginning the product portfolio featured not only the Sirometer but also electric accessories, like power chords and multi-pole sockets.


Employees and family members worked at the factory workshop in the center of Treysa where they had to operate large Bakelite molding presses that required much heat and great strength.


In the 70s the production of electric accessories was given up because of an increasing competition pressure from Asia. From then on the company solely focused on the production of the Treysit Sirometer.


In 1973 Werner Ermel took over the company from his father and introduced the processing of modern plastic material. The Bakelite presses where substituted by self-operating injection molding machines that could be handled with minimum effort.

When Werner Ermel died in 1979 at the age of 44, his wife Inge Ermel and other family members took over the company.
The production facilites were moved into the family's residential house.


In the year 2002 Inge Ermel gave the company to her daughter Iris Beitz for reasons of age. Iris Beitz until today is running the company as a family business.