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 straightedge 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.