The Prüfkoffer is a respirator leak testing device that was made by Dräger. The kit consists of an inflatable test head, a hand pump and various fittings. It performs both positive and negative pressure leak tests. The Prüfkoffer was also sold under the name Test-it 4100.

This example of a Prüfkoffer was used by Freiwillige Feuerwehr Schechingen (Volunteer fire brigade Schechingen) in Germany.