Air nozzles or slits / knives, able to blow air in a quantity controllable from the main control desk. Turla engineers can design overhead aluminium extrusion air cooling systems. These systems are based on a principle identical to that placed beneath the table, where a large single unit blowing station blows the air into an air duct and then the air gets out through air nozzles (slits / knives). Each individual air delivery amount is adjustable from minimum to maximum from the main control desk. Cooling areas can be switched on and off or adjusted.