Duck window insulation film is lightweight, transparent and shrinks fit for a tight, discrete layer of window insulation. It works in the same principle as double glazing in terms of creating a thermal barrier to help keep heat and energy inside and to keep the cold outside.
There is no real reason to take it down once installed, if the film starts to loosen over time, you can simply apply heat using the hair drier to tighten it up again. Cost-effective so if you do need to put a new one up it's a great option.
Having this layer will also help to minimise condensation build up and it's recommended to install on a nice dry day or at least ensure the area is well dry before sealing it off. At least a 7mm gap between glass and frame is recommended to create enough of an air pocket
The kit contains 6.5m2 (7ft x 10ft or 2.1m x 3.0m) film and a roll of window film tape.