O-rings and elastomer seals from the specialist. As an independent manufacturer, C. Otto Gehrckens - known as COG for short - is one of the leading suppliers of precision seals in Germany. As an owner-managed family business in its fifth generation, we have been focusing on expertise for over 150 years. Because only with a deep knowledge of the subject matter can we answer the extremely complex requirements of our customers, including those in highly demanding industries such as medical technology - and convince you with solutions.


We rely on the highest level of materials expertise to prevent production downtimes due to seal damage or leakage with the right precision O-rings. In the world's largest O-ring warehouse, we have over 45,000 items ready for you. O-rings and elastomer seals from standard dimensions to special dimensions made of different materials. Our experience in the development and production of materials forms the basis for offering you proven products in reliable quality - and at the same time scoring with innovations that set new standards for your industry.