This American made product is a huge improvement over other metal roof accessory attachment devices currently on the market. The clamp is one piece and does not require seem feeding up the panel. This patented design fits over the seam for a fast effortless installation. The RC model is designed to fit most seams up to 1" wide. Interior dimensions are 1"wide X 1" high. The aluminum Roof Clamp utilizes a Stainless Steel oval tipped screw that does not pierce or penetrate the panel; therefore it will not void the manufacturer warranty.