Ready-to-install duct unit with 3 or 6 device installation covers for cable routing and for installing installation units of nominal size 9, consisting of duct base (floor pan with side and floor covering support profiles) and duct cover with blindly closed installation opening. Floor pan with retaining tabs for the self-contacting installation of dividers. The scope of delivery includes 6 height-adjustable mounting brackets, 6 screed anchors and levelable cover joint supports: 3 pieces for nominal duct width 400 and 6 pieces for nominal duct widths 500 and 600. Duct cover screwed on when delivered.