This knit non-roll elastic is monofilament which provides elastic with roll and twist resistance. Made of 58-percent polyester, 29-percent rubber and 13-percent polyester monofilament. Useful for necklines, sleeves. It is machine washable and dryable in temperatures up to 200 degrees fahrenheit. Safe with chlorine bleach. Insert into casings or stitch directly to wrong side of fabric. Measures 1/4-Inch in size.