perspective and partially cutaway view of a preferred embodiment of the receptacle unit 1 according to the invention the receptacle unit 1 comprises a rim unit 4 and a tub element 2 the tub element is preferably configured as a substantially rectangular hollow body which is open at one side as in the embodiments of the rim unit 4 shown in fig1 and fig2 the receptacle unit 1 shown in fig4 a shows only half where the half of the receptacle unit 1 not shown is configured to be diagonally plane symmetrical the first direction r 1 in this case runs through the centre of gravity of the receptacle unit 1 and preferably in the direction in which the open side of the tub element 2 is located in the embodiment shown the rim unit 4 is fixed positively with corresponding engagement geometries on the tub element 2 the base contour b of the rim unit 4 is particularly preferably oriented here to the geometry of the open side of the tub element 2 which this is configured to be rectangular in the present embodiment fig4 b shows the detailed view of the connecting region between the tub element 2 of the rim unit 4 characterized in fig4 a it is clear here that the engaging section 22 of the tub element 2 is preferably configured as a projection which engages in a locking section 42 of the rim unit 4 which is corresponding at least in sections in order.