The same high quality ripple foam as our Mad River Fly Boxes from Mill Stream and many others! The Boat Patch works just like an oversized open fly box. Simply mount it on the inside of your boat, canoe, fly tying table, wall etc. using the adhesive backing. If a smaller sized patch is desired, a few snips with a pair of scissors will do the trick. Great for saltwater patterns and lures too! Measures 8 1/2" X 14 1/2".