Series N820.3 diaphragm pumps are double-head, dry-run- ning devices used in a wide range of laboratory applications. They transfer and pump down without contamination. The heart of these very compact pumps is a KNF structured diaphragm. This patented diaphragm was stress-optimized using the Finite Elements method. As a result, we were able to make the pumps smaller while increasing the service life of the diaphragm. The pumps are available in various versions differing in the materials which contact the media.