Abstract: The invention is about a connecting apparatus which ensures the connection of the flexible ventilation ducts to the main ventilation ducts, distribution points and all kinds of fan, device and ventilation equipment, and which, distinctly from the existing connecting apparatuses, is installed by being screwed onto the flexible ventilation duct and thereby where the flexible ventilation duct serves as a natural gasket by being squeezed, and which allows for a more leak-proof, more resistant, snore practical, more economic and more flexible connection.