Flip - Flap Doors are two-way, single-leaf or double-leaf made of high-density polyethylene sheets - a product of the well-known Coil factory. They are made of 15 or 20 mm thick material with a fixed oval finisher, they can remain open at a 90 degree angle and are attached to the opening with a frame on which the door leaves are fixed. They open inside and close immediately "after the passage", preventing the passage of insects, dust, odors and other unwanted elements. They are not affected by external shocks as they are made of extremely durable material which has resistance to sadness, acids and cleaning materials. They have a functional design, long life and in addition no maintenance costs are required. Double-flip-flop doors are manufactured in accordance with DIN EN ISO 1043 technical specifications.