Formerly known as Metrolene, Seralene is a 100 Polyester Overlock thread that is perfect for creating fine, almost invisible seams on light weight fabrics. Thanks to its fine qualities, Seralene is suitable for high quality basting as well as for invisible stitching and decorative work. It also makes an ideal underthread or looper thread. Shrinkproof easy to clean. Recommended needle size: 7080. 2000m2187yds per spool. 4 spools per box. Purchase by the box.