1. Material The inner filling made of cotton linen consists of density foam, providing stability and comfort across the gap. Designed to let you sleep comfortably without feeling the gap between the beds. 2. Practical End insomnia and close the gap between the headboard, wall, and mattress or footboard with this mattress gap pillow. This foam cushion fills the gap, so you won't lose pillows, pets, or children's toys. 3. Wide Application This durable bed gap filler offers comfort and support, as well as convenience. It can not only be used as a double bed bridge or armrest/headrest for wooden sofas but also bridge the gap between the headboard, wall, and mattress. 4. Removable Zipper The pillow cover is removable and features a zipper design, making it easy to put on and take off, as well as convenient for replacement and washing. The zipper is easy to use, comfortable, and practical. The sofa armrest pillow cover can be hand washed or machine washed.