The Kelly Bean Ruler is 5″ wide x 2″ in length, with an equal convex and concave curve. It is clear, 1/4″ acrylic. It has a 1/4″ measure line around the inside edge. The rounded end makes for easy movement, so as not to get caught up in seams. The rounded end can also be used for scallops and half circles. Use with domestic or longarm machines.