The filter housing is round and consists of a filter pot and a filter lid. The filter pot features a special thread, and the filter lid is open towards the inhalation side. There is a filter bed with activated carbon, which is securely fixed by the housing and internal screens. The particle filter is positioned on the inhalation side before the gas filter section. It consists of a single component and has pleated folds. A gas-tight connection is established between the particle filter and the housing. The filter is vacuum-sealed in a polybag to be moisture-proof.