FIELD: installation of electric instruments. SUBSTANCE: the invention concerns the box having, on one side, a case made for installation on the respective wall and forming a seat for installation of the respective instrument and having a hole on the side, where it should touch the tray, and on the other side, a cantilever panel, which begins from the case, respectively, from the hole in the latter, and is designed for local covering of the tray transversely with respect to the latter. In accordance with the invention, the cantilever panel has at least two separate parts made one after the other in length in the width or height of the tray, and namely, beginning from the case, the fixed part made integral with the case, and at least one movable part connected to the fixed one and adjustable in position in respect to the latter. EFFECT: simplified installation of the box and reduced expenditures connected with manufacture. 16 cl, 4 dwg
