The 12'6" SUP outline template has parallel rails through the middle of the board so you can take out sections of the middle to reduce the length without changing the overall shape. No need to specify the length you want when ordering.To make the board wider you simply move the template away from the stringer and draw curves on the blank to extend the outline to the stringer. You can do it free hand, make your own paper template for the extensions, or bend a flexible piece of wood, plastic, or metal to get your extension curve.