outer surfaces of the rims 24 and 26 respectively and provide an additional seal for the whole retracted container a further movable floor element 38 is u00fcrovided above the floor element 36 of the main box element 12 also the larger first secondary box element 14 has a movable floor element which is height adjustable relatibe to the floor element 32 of the secondary box element 14 in fig2 the secondary box elements 14 and 16 are expanded or moved out of the main box element 12 to this end the secondary box elements 14 and 16 are guided by the guiding system 18 the guiding system 18 includes guide rails 46 and 48 which are provided in pairs and can for example retracted into or pulled out from housings not shown of the main box element 12 furthermore the guiding system 18 has supporting beams 50 and 52 which can be attached at their one ends to the side walls of the main box element 12 in the area of the rims 24 and 26 respectively and at their other ends to the outer ends of the guide rails 46 and 48 respectively when the secondary box elements 14 and 16 are expanded or moved out they roll on the guide rails 46 and 48 through the rollers 19 the pairs of guide rails 46 and 48 are interconnected by a longitudinal.