Umpqua UPG HD Standard Foam Fly Box - Red Large The Umpqua UPG HD Fly Boxes were designed with the fly fisherman in mind. These heavy-duty double sided fly boxes are waterproof and are one of the most functional and durable fly boxes on the market. These pocket-sized fly boxes will fit great in any sling, pack, or vest, leaving you extra room for all of your other fishing needs. The UPG HD Fly Boxes are constructed out of TPE (thermoplastic elastomer) injection-molded fly sheets which are lighter than the silicone alternatives and provide the maximum amount of grip. Umpqua opted for see through covers on the UPG HD fly boxes so that, with a quick glance, you can see all of your fishing options and can be prepared when the fish start biting. The Umpqua UPG HD Fly Boxes are a must for every fly-fishing enthusiast.