Product Description The M-D Building Products' Shrink and Seal Indoor Window Kit is installed around entire window to eliminate cold air drafts and frost build-up. Crystal clear film that is easy to install with a hair dryer that shrinks tight and wrinkle-free. Creates dead air space to increase insulating R-Value up to 90-Percent. From the Manufacturer The M-D Building Products' Shrink and Seal Indoor Window Kit is installed around entire window to eliminate cold air drafts and frost build-up. Crystal clear film that is easy to install with a hair dryer that shrinks tight and wrinkle-free. Creates dead air space to increase insulating R-Value up to 90-Percent.