A flash collar is meant to sit at the base of your flagpole and cover the area where the pole meets the ground. Our flagpole flash collar is made from aluminum for year-round, all-weather outdoor display. This flagpole base collar comes in several different sizes to fit a variety of different flagpoles. Our flash collars are all 12 inches across. They’re sold with 3-inch to 10-inch center holes to accommodate 7 different pole diameters.