Dritz-Omnigrip Combo Pack. Quilter's Rulers are plastic injection molded rulers with clean, crisp, accurate lines. The molded lines keep fabric from slipping, allowing for fast, accurate rotary cutting. There are 1/2 and 1/4 markings and has 30, 45 and 60 degree lines. Black markings. For use with rotary cutters and straight edge blades (items not included). Contains one 10-1/2x10- 1/2 inch quilter's square ruler, one 8-1/2x8-1/2 inch quilter's square ruler and one 6-1/2x6-1/2 inch quilter's square ruler. Each has 1/2 inch seam allowances. Made in USA.