3M Interior Transparent Weather Sealing Tape, 1.5-Inch by 10-Yard Weatherproofing tape For interior use in sealing cracks around doors & windows Moisture resistant 3M sealing tape measures 30 inch long Weather tape is flexible conforms to angles and curves Seals cracks to reduce energy loss Decreases heating costs Shrinks tight for wrinkle-free, clear-as-glass results Increases R-value by 90% over an average single pane window.