The Q75 Series landing door is produced in a two-door telescopic and four-door central version. It is useful for use in compartments where the space necessary for placing the mechanism and thresholds is limited. It differs from the corresponding Q Series models in terms of the size of the threshold profile and of the mechanism which is reduced from 90 to 75 mm. With openings up to 1150 mm for both versions with two and four doors, in Standard execution and in certified fire-rated versions in class E up to 2 hours of tightness.