Abstract: A device for cooling hot rolled flat products in such a way so to deliver to the product a relatively long, very thin, low turbulence blade of water which can be adjusted as to flow rate transversely of the product and so can adjust the cooling conditions of the product transversely of the product. The device comprises an elongated water delivery chamber having a linear slit that extends across the product to be cooled. The chamber is bounded longitudinally by guide walls that converge toward the slit and is divided transversely into a plurality of smaller chambers by a plurality of baffles transverse to the length of the chamber. Each of the smaller chambers is in communication with the water supply via at least one adjustable flow regulating device. The baffles are integral with the walls of the chamber and terminate toward the slit short of the outer edge of the slit.