Thank you for visiting! ( *´艸｀) These are arm covers for kids. When they're drawing, playing with clay, or doing all sorts of fun activities, sleeves get incredibly dirty. If they wear these, they don't have to worry about getting their favorite clothes dirty. ( ^ω^ ) The fabric is double gauze, so it's gentle on the skin. The elastic part is designed with varying arm sizes in mind, so the elastic is cut long and tied loosely. Please adjust the knot to fit your child's arm size, and tuck the knot inside. They are reversible, so you can enjoy your favorite pattern depending on your mood. The length is approximately 26cm.