KLASSE-5 German-engineered steel machine ballpoint needles. With a more rounded tip than the universal needle, the ball point is designed to push the fabric fibers apart. This prevents skipped stitches in knit fabric as well as runs and puckers. Best for: cotton knits, interlock, rib knits, fleece, double knit, and most knit fabrics. Use with polyester or polyester/cotton threads.