Easy to Install: No drilling and tools required. 1. Clean the dust on the window frame first, measure the four sides of window. 2. Cut two sets of 4 Velcro strips - one set for the casement, and one set for the window frame, stick the Velcro trips on a specific side of the casement and the window frame, then attach the window seal cover on the Velcro trips. 3. Rotate the coupler onto the hose, and then attach the coupler on seal cloth.