Klasse Machine Needles go through 163 quality checks, earning the industry's highest quality rating for stability at high speeds, seam appearance, clean stitch holes, and precise and uniform stitchability. Each needle has a unique number stamp identifying its point style and size when separated from the package. Sharps needles have an extra sharp point that penetrates tightly woven fabrics. You get perfectly straight without skipping or puckering. Use on silk, microfiber, rayon, synthetic suede, and densely woven lightweight fabrics.