Black walnut two layers 60 Black walnut two layers 80 Black Walnut two layers 100 Black walnut Two layers 120 Black Walnut Three layers 60 Black Walnut Three layers 80 Black Walnut Three layers 100 Black Walnut Three layers 100 Black Walnut Three layers 100 Black Walnut Three layers 100 Black Walnut Three layers 100 Black Walnut Three layers 100 Black Walnut Three layers 100 Black Walnut Three layers 100 Black Walnut Three layers 100 Black Walnut Three layers 100 Black Walnut Three layers 100 Black Walnut Three layers