Create 3 inch or 6 inch Square on Square blocks. No calculation needed - all the cutting measurements are printed right on the tool! Trimming each round as triangles are added creates perfectly square, uniform blocks. The popular Snail's Trail block is now easier than ever - simply change the colors of the triangles! The ruler slides easily over the fabric until pressure is applied. Then, our exclusive gripper holds the fabric in place while cutting, eliminating slipping and miss-cuts! Size - 6-1/2in x 6-1/2in