ASSEMBLE INTO MANY DIFFERENT SIZES AND SHAPES. The interlocking boards are simple to put together and stay firmly in place, to fit your individual project. With this set, you can configure in a 3x3 square or any other shape to fit a longer or different sized piece. If you order multiple sets of this product, they will also fit together to form a larger blocking surface for knitting, crocheting, needlework or lace projects. GRID LINES FOR PRECISE BLOCKING.