3M Indoor Insulator Kit, 2-Window – Link
Amazon has this currently marked down to its lowest price at only $4.98.
Note that this is an Add-on Item which ships with a $25 Amazon order.
With the 3M indoor window insulator kit, you can lower your heating bills during the winter and make your home more energy-efficient.
- Included: (1) 5.16′ x 7′, (2) rolls of tape each 1/2″ x 500″
- Insulates two 3′ x 5′ windows
- Lowers heating costs and saves energy
- Applies easily, shrinking tight, wrinkle-free and clear on glass
- Increasing the R-value of single pane window by 90%