Maxi-Lock Cone Thread 3000 Yards-Blue. AMERICAN & EFIRD-Maxilock Thread. Quality 100% polyester thread for the serger. Maxilock offers even strength for high speed sewing machines. 3000 yard cone. Imported. Sold Individually Please note: If there is a color/size/type option, the option closest to the image will be shipped (Or you may receive a random color/size/type).