Cold rolled steel parts for use in construction work, together with laminated plasterboard and gypsum board products where the frame is not load-bearing. Omega-shaped profile, used in semi-direct ceiling and cladding panel systems. The side in contact with the board is knurled to facilitate screw attachment. It has a nominal width of 82 mm, with wings measuring 16 mm. It is made of 0.55-mm thick Z140 galvanised steel plate.