Aluminum is the most common and will stand up better against rust and corrosion over time. All in all (To sum up), when purchasing an extendable flag pole make sure to pick a material that meets both your needs and budget – with careful consideration of these points you should have no trouble finding the perfect one for your situation!How to Design a Customized or Uniquely-Shaped Extendable Flag PoleDesigning a customized or uniquely-shaped extendable flag pole can be an exciting and rewarding project! Creating a unique structure that will last for years to come requires careful planning and attention to detail. (First of all), it's important to consider the purpose of the flagpole. Also, consider purchasing a flag pole with an adjustable height so you can adjust the height of your flag based on wind conditions or other factors.