Convex housing (1) for use on a base plate of an ostomy apparatus, the convex housing (1) comprising an annular ring (5) defined by an outer edge (6) and an inner edge (7) defining a hole through (8), said ring (5) having greater flexibility around a first axis that is perpendicular with respect to the central axis CC of the through hole (8) compared to the flexibility around a second axis that forms an angle with respect to to the first axis and which is perpendicular with respect to the central axis CC of the through hole (8), characterized by the fact that the convex housing (1) comprises an outer flat surface (20) extending in a first plane perpendicular with respect to to the central axis CC of the through hole (8), the outer flat surface (20) extending radially inwardly from the outer edge (6) and changing to an intermediate inclined surface (21), the intermediate inclined surface (21) extending ia radially inwards from the outer flat surface (20) to an inner flat surface (22), the inner flat surface (22) extending in a second perpendicular plane with respect to the central axis CC of the through hole (8) and extending radially from the surface (21) inclined intermediate towards the inner edge (7) that defines the through hole (8).Carcasa convexa (1) para usar en una placa de base de un aparato de ostomía, comprendiendo la carcasa convexa (1) un anillo anular (5) definido por un borde exterior (6) y un borde interior (7) que define un orificio pasante (8), teniendo dicho anillo (5) una flexibilidad superior alrededor de un primer eje que es perpendicular con respecto al eje central C-C del orificio pasante (8) en comparación con la flexibilidad alrededor de un segundo eje que forma un ángulo con respecto al primer eje y que es perpendicular con respecto al eje central C-C del orificio pasante (8), caracterizada por el hecho de que la carcasa convexa (1) comprende una superficie (20) plana exterior que se extiende en un primer plano perpendicular con respecto a
