Lower part with mounting cover made of sheet steel for BKB 250x85mm, length 2m. Electrical installation duct system for flush installation in rooms with dry-maintained floors. The 2m duct system consists of a floor tray and 2 system supports that serve to support the upper parts, a 2m floor stop rail arranged on the room side that can be adjusted to a floor covering height of up to 25mm, and 2 mounting covers that protect the system from damage and dirt during the construction phase. The upper part with base profile is earthed using attached earth lugs. The duct system is to be installed horizontally on the subfloor and aligned to screed height using leveling screws, adjustment range min. 96mm max. 210mm. The assembly must be carried out before the screed is laid.