The system GROOVE consists of a pair of ML_30 profiles installed opposite each other, bounding the aperture in the plasterboard, and covered with sheet steel painted in standard matt black or white.
The cover is made using moulds with an 85mm inner curvature radius, to avoid unsightly corner folds in the sheet metal. A further advantage is the male/female overlap folds, on each side, to obtain an excellent finish and to avoid any gaps.
The system can be realizable without the sheet steel cover, by building the enclosure using plasterboard, as shown below. This type of application can be useful in cases where you want to obtain a specific aperture size, different to the standard 70mm and 140mm imposed by using the covers.