Features and added value: One inspection flap for wall and ceiling, universally applicable for plank thicknesses 20 and 25 mm, flush-mounted plasterboard Diamant GKFI (no filling of the lid required), little opening path of the closure and low installation depth in the cavity, can be retrofitted, fit even when Befliesung in the sanitary area. Application: Universally applicable for ceilings and walls, z. B .: Knauf mounting walls, attachment shells, suspended ceilings.