The ASD filter box FDAZ292 is used in environments with a high dust concentration. It is installed in the pipe system upstream of the aspirating smoke detectors FDA to provide protection against contamination. The ASD filter box filters dust and dirt particles out of the pipe system before they can get to the aspirating smoke detectors. This increases the service life of the aspirating smoke detectors. The ASD filter box comprises a plastic housing (ABS) and an ASD filter set with three separate filters with pores of different sizes (coarse, medium, fine).