Window Bundle

Window consisted of strips of foil-backed paper dropped from an aircraft in bundles during a raid, and was designed to interfere with German radar.

Window was a cheap and simple radio countermeasure used to disrupt the German air defence system by swamping radars with false targets. It was initially effective but the Luftwaffe responded with its own countermeasures. The use of physical countermeasures to protect aircraft continues to this day.