2540. Aurifil 50 thread comes on a 1300 meter spool. Aurifils 50wt thread  (Orange Spool) is the most versatile and popular Cotton threads. 
 
A wonderful Egyptian Cotton that is very strong, with a lovely smooth appearance, great for:
English Paper Piecing
Quilting ; topstitching 
A great basic patchwork thread
Needle Turn Applique,
Bobbin and Machine Lace,
Machine Applique (Straight Stitch, ZigZag, Blind Hem and Blanket Stitch,)
Machine Embroidery,
Dense Machine Quilting,
Subtle Machine and Longarm Quilting,
Basting, Whole Cloth and Micro Quilting, and Dense Background Designs.