This is 4 yards of Steam-A-Seam 2 Regular fusible web. It is the top of the line of fusible web products. It is used with a steam iron on the cotton setting. It makes a permanent bond when you pre-wash your fabric before applying. I use it on all my quilt and craft projects and I love it. It is really hard to find in a 24" width, especially on the roll and not folded.