The Do it Best Extra Strength Indoor Window Insulation Kit is designed for high-traffic areas, offering twice the thickness of standard film to resist accidental punctures and increase R-value by up to 90%. The crystal-clear plastic sheet shrinks tight and wrinkle-free with a simple hairdryer, providing a neat, energy-efficient seal. It easily installs on metal, painted, varnished wood, or vinyl-clad window frames using the included double-face tape.