American & Efird Maxi-Lock 100% polyester quality thread for the serger. Maxi-Lock is used by major serger manufacturers to test their machines and to demonstrate them in retail settings before each sale. Its soft finish disguises a strength that holds up under the most vigorous seam work. Its consistency, beginning to end, makes it easy to set and maintain tensions. Maxi-Lock meets the demands of serger sewing like no other thread, withstanding the high speeds and tensions that are unique to serging. 3,000 yard Cones