Frost King premium window and patio door insulation kit is heavy duty and can be used in indoor or outdoor applications. For situations where toughness and extra strength are important, this insulation kit will stand up to the challenge. It is twice as strong as Frost King standard insulation kit and the double-sided tape is extra wide. Insulation film on windows helps increase their R-values by up to 90 percent, thus providing energy-saving efficiency. Insulation window kits also stop drafts and help lower your utility bills.• Lowers heating costs and saves energy• Protects against drafts, rain, snow, dust and pollen infiltration• Iinsulate one extra-large window or patio door based on patio door measuring 7 feet x 10 feet• Crystal clear will provide a transparent view• 5/8" wide double-sided roll of tape• Can be used indoors and outdoors