Made especially for sewing through densely woven materials such as denim or imitation leather. It is both strong and sharp. Some quilters use it when sewing through many layers of fabrics, especially high thread count batiks. The shank(top part) of these needles have one flat side and one rounded side. These will fit all “household” models of Brother, Janome, Singer, Pfaff, Bernina, Viking, Elna, Kenmore, Baby Lock, Simplicity, Necchi, White and many others.