Klasse&#39; Triple Needle Size 3.0mm" /> 1 German-Engineered Steel Machine Needles This needle type is excellent for heirloom sewing and decorative topstitching. The size indicates the distance between the spacing of the needles. Since the needles are fixed on a nylon block, use it at slower speeds and not for prolonged periods of time. With a unique curved design at the clearance-above-the-eye "CAE" stress point distributes pressure equally which makes Klasse needles much stronger then other flat conventional needles