Oh what fun you are going to have with this no-slip ruler. A fast, fun way to make half square triangles. Uses popular 10” and 5” squares of fabric to give you quick and accurate half-square triangles in 4 1/2 (4” finished size) and 2” (1 1/2” finished size). Also a great tool for squaring up other blocks because of the easy to read lines and NO SLIP SURFACE. You will find this is a handy ruler to have around.