DASCO's access doors are hinged type return air grilles. They are mainly for maintenance purposes, hence are constructed of hinged double frame, with nut locking devise to open and close easily. Special types are available with an aluminium sheet cover for better architectural appearance . DASCO's access doors are made from extruded aluminium construction. They are multi parallel fixed blades having aerofoil sections and are fixed at 45º inclination angle either in the horizontal or vertical directions. The double- hinged frame is of an attractive curved-back type, however, it can be supplied in flat type as optional. Dasco access doors can also be provided with cleanable type air filter to the required thickness. Access doors are also available with aluminium cover sheets and special access door frames are available to fix gypsum board.