This OLFA mat rotates so you don t have to. It features a non-slip, stationary bottom layer and an interlocking top cutting mat that rotates 360 degrees. Use the mat to cut squares, triangles, diamonds, circles or any shape that requires turning. Its special self-healing surface regenerates in between uses. You ll find plenty of uses for the mat: quilting, sewing, cutting out patterns, rotary cutting, general crafting, scrapbooking and more. The mat is designed to not only protect your work surface, but to extend the life of rotary blades as well. Choose the size that best suits your needs: 12" or 17".