When riding in parades or other performances, a saddle flag carrier is meant to hold the bottom of a flag pole and carry the majority of the weight. To keep the flag balanced, the rider then holds higher up on the pole.
Flag carriers come in a variety of pole sizes, so make sure you know which one you will need. Most can accommodate poles with a diameter of 1 1/8 or 1 1/4 inches.
Getting the knack of riding with a flag for both you and your horse takes some experience. Not only will you require strength and coordination, but you will also need to be able to control your horse with just one hand.