This expert-level Square-Up Ruler features a 9.5" x 9.5" outer frame and a 7.5" x 7.5" inner square, designed for precise cutting and squaring of quilt blocks. Unique corner cutouts allow your rotary cutter to make inside cuts effortlessly, enhancing versatility and accuracy. This ruler is an essential tool for quilters seeking professional results and efficient block preparation.  Made from 1/8" thick acrylic, the ruler is sturdy and useful!