Klasse Leather Machine Needles. Designed and developed in Germany Klasse needles are engineered to meet the most exacting industrial performance standards. Klasse needles go through 155 quality checks earning high industrial quality rating for: stability at high speeds seam appearance clean stitch holes and precise and uniform stitchability. A unique curved design at the critical clearance-above-the-eye stress point distributes pressure equally and makes Klasse needles much stronger than conventional flat needles.