The slanted crown form angled at 8in is 5in deep and will create crowns from 10in X 10in up to 56in X 56in. Select the appropriate sections slide them together adjust to the chimney dimensions and place on the chimney. Then pour in your crown mixture and allow it to cure. These forms allow for a minimum 1.5in overhang or drip edge. Note – To make a complete set you need to order two pair of forms. 20 Inches – 56 Inches.