From Studio 180 Designs: Now you can make those tough elongated diamond units needed for any Storm at Sea project with ease and success. But remember, this is a basic unit that can combine with any of the other fundamental units to create many, many other interesting designs and quilt projects. You'll precision cut the center diamond, then sew on side triangles to create an oversized unit that you'll trim down to the perfect size. Ruler Size - approx. 11" x 11" Unit Sizes available on tool - 5 options from 1" x 2" finished units to 5" x 10" finished units in whole inch increments Step by step illustrated instructions Illustrated instructions for left hand cutting and trimming Fine lines for higher accuracy " WATCH THE VIDEO" and learn just how easy it is!!