the Life of Artificial Flies What Is The Dry-Tech MRT Fly Box? Conveniently dries your wet flies inside the box Eliminates hook corrosion in freshwater & saltwater flies Extends... the durability, lifespan, and investment in your flies Waterproof, airtight, rugged, durable lifetime construction Moisture that becomes trapped inside fly boxes can be damaging... to flies. Replacing wet flies in your fly box or fishing in wet or humid conditions can cause hooks to rust and fly tying materials to deteriorate. This is particularly true with salt...