Upgrade your outdoor and upholstery projects with Coats Ultra Polyester Bobbins #U Size 138 Black (144 pack). These bobbins feature continuous filament bonded polyester thread, delivering high strength and durability for heavy-duty sewing tasks. Designed for industrial and commercial sewing machines, the thread is heat set for stability, minimizing shrinking and expanding during use. Each bobbin holds approximately 33 yards of 3-ply thread with a break strength of about 21 lbs, making it ideal for thick fabrics, leather, marine fabric, and outdoor products. The black thread resists ultraviolet rays, mildew, and microorganisms, ensuring long-lasting performance in demanding environments. This 144-pack offers plenty of thread for large-scale projects, and the U Size 138 bobbin is compatible with needle sizes 22/24. Perfect for furniture upholstery, seat trims, and marine applications, this polyester bobbin thread supports reliable, weather-resistant stitching for professional results.