Infinitely adjustable blocking boards for crocheted hexagons. Comes with 1 - Blocking Board 1 - Post alignment guide 6 -20cm (7.8") posts 5 - MAT Sets (30 pieces) Notes: 1. Additional MAT Sets can be purchased on my other listing "MAT Sets for the Large Hexagon Adjustable Blocking Board" Block any size from 1-3/8th inches (3.5cm) to 8 inches (20.3) on a side.