Multi-Purpose: High flags provide a safe view for young and old and can work on different types of bikes, bike trailers, or any other outdoor recreational vehicles, such as submarines and outdoor tents Adjustable height: there are two sets of Bike Safety Flag, each group of 4 fiberglass poles; 1.5 feet to 6 feet flexible, ideal for low children's bicycles and electric cars, one is enough; maximum height of about 6 feet, different flagpoles can be adjusted to varying sizes as needed Tear-resistant and Waterproof Flags: All flags in the package are polyester, printed in full color, not easily torn, waterproof, and easy to clean Bright Color Warning: Easily attached to the rear axle of your bike for maximum visibility, the orange safety sign allows for maximum vehicle visibility BEST GIFT: This is a great gift for outdoor enthusiasts on bikes, kids, and seniors in wheelchairs