This 2-1/2 inch x 24-1/2 inch rectangular ruler is the perfect size. It fits snugly on your mat with no overhang, and cutting straight across the stud has never been easier. The ruler features easy-to-read black and white markings printed on 1-inch grids marked in 1/8-inch and 1/4-inch increments. Use the easy-to-read black numbers (printed on white dots) and the 1/4-inch gripping sides to cut whole inches. The 1/4-inch dashed lines printed on two adjacent sides help trim seam allowances. Use the patented Turn-A-Round feature, designated by the easy-to-read white numbers (printed on black dots) and the 1/2-inch gripping sides, to add the 1/2-inch seam allowance. Use the white 45-degree angle to trim half-circles in whole-inch increments. Use the black 45-degree angle to trim half-circles in half-inch increments. An additional black 45-degree line is positioned to intersect 1/4 inch from the outer edge. Use these markings to square flying goose units and squares set on the dot. The ruler also features a 30-degree/60-degree angle. White horizontal and vertical lines are printed on the rectangle to make the center of the ruler easily distinguishable. Use these lines to cut stripes and fussy edges. The ruler glides easily over fabric until pressure is applied. Then, our unique grip holds the fabric in place while you cut, eliminating slippage and miscuts. Overall size: 2-1/2 inches x 24-1/2 inches