Originally got from screwfix as it advertises for all windows and doors, however it is not the case and was far too big for mine.
Window Door Seal Cloth Air Conditioner Window Kit Portable Window Door Seal Kit
Air Conditioner Window Door Seal Kit Universal Window Door Seal with Zipper for
Home Sliding Window & Door Seal Cloth Air Stop Waterproof Airlock Door Seal
AirLock Window Door Seal for Mobile Air-Conditioning Units Door Cloth Sealing 4M
Air Conditioning Window Door Seal Window Weather Sealing Cloth Portable with
