Pack of 100 Organ 7X4DIA Diamond Point Leather Sewing Machine Needles. Needle system : 7X4DIA Also sold under needle system number's : 794DIA Needle Length, butt to needle eye : 60.10mm Total length : 69.40mm Shank Diameter : 2.5mm The Diamond Point (DIA) needles are generally used on hard and dry leathers. The blade cuts fibers so that the needle does not have to separate them. Leather needle has the shape like a wedge at the point which gives it superior piercing power for unyielding fabric such as real leather, suede or heavy vinyl. This needle makes a clean, large hole as it enters the fabric. It is better to tie or seal thread ends rather than back-stitching to secure. Sew accurately since removing stitches and restitching will leave hole markings. Organ 7X4DIA needles are available in following sizes. Please select the size from the drop-down option menu : Singer Size 24 (Metric Size 180) Singer Size 25 (Metric Size 200) Singer Size 26 (Metric Size 230) Singer Size 27 (Metric Size 250) For Singer 7 Class, 34 Class, 144 Class machines and other comparable extra heavy sewing industrial machines.