Made from high-density foam, the Foam Fly Patch from White River Fly Shop makes storing and locating any size fly easy. It can be attached to your fly fishing vest, backpack or any other convenient place. Available: Triangle Slit Fly Patch Featuring 10 slotted triangle storage rows. Safety pin connection. 3-1/2 x 2-1/2. Rippled Fly Patch Offers six ribbed storage rows. Includes an alligator clip and hook-and-loop patch. 4 x 2-1/4. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Fly Boxes.