The large Master micro-slit foam fly boxes store, organize and protect your flies. It is a home, car, or base storage fly box where you can store all your flies for an entire season. You can easily select the flies you need for any specific time and place from the Master Fly Box and place them in a smaller size fly box to take with you on the water. This not only prevents you from carrying a lot of flies you don't need, it also makes it easier for you to select flies when you are on the water. You don't have to search through a lot of flies you don't need at the time.