Features and added value: Inspection hatch in the system tested for Knauf cantilever fireboard cover K219.de, tested fire protection requirement F90 optional in combination with air and dustproof and smoke-proof. Application: Installation in Knauf cantilever fireboard ceiling K219.de with planking thickness 20 + 20 mm (F90 from below and from above) and 2x 20 mm Fireboard (F90 from below), with additional substructure / replacement.