MEGA 400 ALL Purpose SEWING QUILTING SERGER THREAD from ThreadsRus 100% Polyester Sewing Machine Threads 400 Spools Packed in 4 boxes of 100 spools each. 90 Different Colors in Each box. 100% Color Fast. will NOT Bleed or Run in Hot or Cold Water. Very High Tensile Strength, for high speed stitching Can be used for Hand Sewing / Machine Stitching / Serger / Light Quilting