The external window sealing strip is a combination of non-woven fabric and membrane allowing steam diffusion. Provides an external window seal, resistant to rain and other atmospheric conditions. Provides steam-permeability of the external connecting joints at the windows to protect them from the rain. It is used for sealing joints between windows and doors and the building shell. The external sealing strip has self-adhesive tapes with long-lasting adhesion. Suitable for all types of joinery. It is fireproof, waterproof and breathable with the possibility of painting and plaster on both sides. It has 3-month UV resistance.