Singer's Leather Needles come in a five-pack and contain three 90/14 needles and two 100/16 needles. The size 14 needle is best used with thinner pieces of leather, and the size 16 is more suit thicker materials like plastics or PVC. They have a wedge point that allows them to pierce fabrics without tearing or stretching more easily. Singer's 130/705 Leather Needles can be used with most domestic machines.